JP6544560B2 - Micro-object characteristic measuring apparatus and micro-object characteristic measuring method - Google Patents

Description

  The present invention relates to a minute object characteristic measuring apparatus and a minute object characteristic measuring method, and more particularly to a minute object characteristic measuring apparatus and a minute object characteristic measuring method for measuring a characteristic of a minute object.

  In recent years, techniques for measuring the properties of minute objects (for example, adhesive force, image force, charge polarity, electrical resistance, dielectric constant, etc.) have been actively developed.

  For example, Patent Document 1 discloses an adhesive force measuring device that measures the adhesive force of powder by bringing the powder and the plate-like member pinched by the pinching member into proximity, contact, and separation. .

  However, in the related art such as Patent Document 1, the measurement efficiency can not be improved.

The present invention is opposed to the plurality of holding members capable of holding a minute object, the driving system capable of independently driving the plurality of holding members, and the minute object held by any of the plurality of holding members. A driving device capable of driving one of the holding member holding the minute object and the cantilever in a direction in which the minute object held by the holding member and the cantilever approach and separate from each other; The plurality of holding members includes two holding members provided to face each other, and each of the two holding members has two arms for holding the minute object, at least one of the two holding members are rotatable der Ru fine fragment characteristic measuring device about the axis parallel to the longitudinal direction.

  According to the present invention, measurement efficiency can be improved.

It is a figure which shows schematic structure of the micro thing characteristic measuring device of 1st Embodiment. It is a figure for demonstrating the micro / nano tweezers which is an example of a holding member. FIGS. 3A and 3B are diagrams (part 1 and part 2) for explaining a micro / nano pipette which is an example of the holding member. FIG. 4A is a view showing a state in which a micro object is collected using the holding member, and FIG. 4B is a view showing a state in which the micro object held by the holding member and the cantilever are opposed to each other. It is. It is a figure which shows schematic structure (the 1) of the micro thing characteristic measuring apparatus of 2nd Embodiment. It is a figure which shows schematic structure (the 2) of the micro thing characteristic measuring device of 2nd Embodiment. 7 (A) and 7 (B) are diagrams (the 1 and 2) which show schematic structure of the micro thing characteristic measuring apparatus of 3rd Embodiment. It is a figure (the 1) for demonstrating the micro thing characteristic measuring device of Example 1 of 4th Embodiment. FIGS. 9A and 9B are graphs showing the relationship between the opening width between the arms of the holding members 1 and 2 and the size distribution of minute objects. It is a figure (the 2) for demonstrating the micro thing characteristic measuring device of Example 1. FIG. FIGS. 11A to 11E are diagrams (Nos. 1 to 5) for describing a method of holding a minute object between holding members in the first embodiment. 12 (A) to 12 (E) are diagrams (Nos. 1 to 5) for explaining a method of separating a plurality of agglomerated minute objects using two holding members in Example 1. . It is a figure (the 1) for demonstrating the micro thing characteristic measuring device of Example 2 of 4th Embodiment. FIG. 14A and FIG. 14B are diagrams (part 2 and part 3) for explaining the minute object characteristic measuring apparatus according to the second embodiment. It is a figure for demonstrating the micro thing characteristic measuring device of Example 3 of 4th Embodiment. 16 (A) to 16 (C) are diagrams (parts 1 to 3) for explaining a method of separating a plurality of aggregated micro objects by using two holding members in Example 3. . It is a figure for demonstrating the micro thing characteristic measuring device of Example 4 of 4th Embodiment. It is a figure for demonstrating the micro thing characteristic measuring device of Example 5 of 4th Embodiment.

First Embodiment (Principle of the Present Invention)
Hereinafter, the basic principle and mechanism of the present invention will be described as a first embodiment based on FIGS. 1 to 4. FIG. 1 shows a schematic configuration of a minute object characteristic measuring apparatus 100 according to the first embodiment. The following description will be made using an XYZ three-dimensional orthogonal coordinate system in which the Z-axis direction shown in FIG.

  The minute object characteristic measuring apparatus 100 includes, for example, a holding member 10 capable of holding a minute object, a cantilever 20 (cantilever), a laser displacement meter 30, a fixing jig 40, a fine adjustment stage 50, a processing device 60, and the like. There is.

  The holding member 10 is a member capable of holding minute objects one by one. As the holding member, as shown in FIG. 2, those referred to as micro / nano grippers or micro / nano tweezers which hold micro objects between both ends and held as shown in FIG. 3 (A) and FIG. 3 (B) As shown, a micro / nanopipette can be used which holds (adsorbs) by sucking a minute object.

  Here, the size of the minute object suitable for measurement is such that the maximum diameter that can be held by the holding member 10 falls within the range of 10 nm to 1 mm, and the more preferable size is in the range of 1 μm to 100 μm. It is the one to enter. As a specific example of the minute objects, toners used in copying machines, medicines, food products, powders used in constituent materials of electronic devices, minute foreign substances attached to electronic substrates, etc., and biological materials such as cells can be considered. Be

  Examples of the powder include, in addition to toner particles, constituent materials of a 3D printer (about several um to several tens of um), iron powders for toner charging (about 30 um to 100 um), liquid crystal spacers (about several um), etc. Be

  The holding member 10 is, for example, an XYZ three-dimensional movement mechanism (hereinafter also referred to as "three-dimensional movement mechanism") capable of independently moving the holding member 10 in the X axis direction, Y axis direction, and Z axis direction. , A sampling position (see FIG. 4 (A)) at which the minute objects can be collected in a sampling area (for example, a sample table to which the minute objects are dispersed or a member to which the minute objects are attached) It is possible to move between a measurement position (see FIG. 4B) which is a position at which the minute object faces the cantilever 20 (here, the position on the + Z side of the cantilever 20). The operation of the holding member 10 when holding (collecting) a minute object by the holding member 10 is manually performed via the operation unit. Instead of the XYZ three-dimensional moving mechanism, for example, a combination of a tilt rotation mechanism capable of tilting the holding member 10 and an XY two-dimensional moving mechanism for moving the holding member 10 along the XY plane may be combined. The operations of the XYZ three-dimensional movement mechanism, the tilt rotation mechanism, and the XY two-dimensional movement mechanism may be automatic or manual.

  Fixing jig 40 is, for example, a member (for example, a rectangular parallelepiped member) having an upper surface and a lower surface parallel to the XY plane and one side surface (a side surface on the + X side) parallel to the YZ plane. It is done.

  The cantilever 20 is, as an example, formed of a thin plate-like member, the fixed end side portion is fixed to the upper surface of the fixing jig 40, and the free end side portion (overhalf portion) protrudes from the fixing jig 40 to + X side And the minute object held by the holding member 10 positioned at the measurement position.

  As the cantilever 20, for example, a cantilever for an atomic force microscope (AFM: Atomic Force Microscope) with a very high degree of smoothness can be used, but a cantilever with an appropriate spring constant and material is selected according to the measurement content. There is a need. Although a cantilever for an atomic force microscope is usually provided with a tip for scanning a sample at its free end, it is not always necessary to provide a tip here. That is, when using a tipless cantilever or a cantilever provided with a tip, it is necessary to fix the tip so that the tip faces the laser displacement meter 30 side instead of the minute object side. The cantilever 20 preferably has a high degree of smoothness, and may be one other than one for AFM.

  The laser displacement meter 30 is fixed to the side surface on the + X side of the fixing jig 40 so as to face the cantilever 20. As described above, since the laser displacement meter 30 is integrally provided with the cantilever 20 via the fixing jig 40, it is possible to measure the displacement of the cantilever 20 due to the deformation (warpage) with high accuracy.

  The laser displacement meter 30 is not necessarily limited to a specific product (spec), but its spot size is about the same as the width of the cantilever 20 or more than the width of the cantilever 20 so that deformation of the cantilever 20 can be monitored. It is desirable to be small. In addition, it is desirable that the measurement resolution be high so that minute deformation of the cantilever 20 can be detected, and specifically, a resolution of about 1 nm is required.

  The fine movement stage 50 is a movable table which can be finely moved in the Z-axis direction. The fine movement stage 50 needs a position resolution on the order of nm, and specifically, it is preferable to use a piezo stage (a stage using a piezo element as an actuator). Note that instead of the piezo stage, for example, a stage using a high precision stepping motor or the like as an actuator may be used.

  Therefore, a driving device capable of minutely driving the cantilever 20 in the Z-axis direction is configured, including the fine movement stage 50 and the fixing jig 40. Alternatively, the cantilever 20 may be directly fixed to the fine movement stage, and the driving device may be configured by only the fine movement stage.

  The processing device 60 controls the fine movement stage 50, acquires (collects) the measurement result of the laser displacement meter 30, and obtains the characteristics of the minute object based on the measurement result.

  As a specific flow up to the start of measurement, the three-dimensional moving mechanism is operated as needed to position the holding member at the sampling position on the sampling area, and the holding member 10 is manually operated to The sample is collected (see FIG. 4A), and the three-dimensional moving mechanism is operated to move the holding member 10 holding the minute object to the measurement position where the minute object faces the cantilever 20 (see FIG. 4B). .

  Note that, instead of moving the holding member by the three-dimensional moving mechanism, for example, the sampling area and the fine movement stage 50 perform a two-dimensional moving function in the XY plane, and the holding member 10 performs a one-dimensional moving function in the Z-axis direction or It may have a tilt rotation function.

  In addition, an observation system (microscope function) is necessary for holding the minute objects scattered / attached to the sampling area by the holding member 10 or for positioning when bringing the minute objects close to or in contact with the cantilever 20. However, specific means are not limited as long as minute objects of several um size can be recognized, and any of, for example, an optical microscope, an electron microscope, and an atomic force microscope may be used.

  Hereinafter, a specific measurement example by the minute object characteristic measuring apparatus 100 will be described.

Image force measurement
A method of measuring the image force depending on the charge amount of the minute object will be described. Here, since the minute object characteristic measuring device 100 is a device that measures “image force” which is one of the characteristics of the minute object, it may be called “a minute object image force measuring device”.

  In this measurement method, by bringing the minute object held by the holding member 10 close to the cantilever 20, the mirror image charge (induced charge) of the same polarity and opposite to the charge held by the minute object is induced in the cantilever, The image force acting between the object and the cantilever 20 is measured using the laser displacement meter 30 installed on the back side (−Z side) of the cantilever 20.

  More specifically, the holding member for holding the minute object located at the measurement position is moved in the −Z direction by the three-dimensional moving mechanism to bring the minute object and the cantilever 20 close to each other. Then, the processing device 60 minutely moves the fine movement stage 50 in the + Z direction to further bring the minute object and the cantilever 20 closer, and the laser displacement meter 30 measures the amount of warpage (deformation amount) of the cantilever 20 and the measured value Are output to the processing device 60, for example, every several milliseconds. The processing device 60 starts the control of the fine movement stage 50 described above and the acquisition of the measurement value from the laser displacement meter 30 when receiving the processing start request via the operation unit.

  The processing device 60 moves the fine movement stage 50 until the micro object and the cantilever 20 come in contact with each other. The processing apparatus 60 determines whether or not the minute object and the cantilever 20 come in contact with each other based on the measurement value of the laser displacement meter 30 (displacement of the cantilever at the time of contact). The distance between the micro object and cantilever 20 before the start of measurement, that is, before the start of movement of fine movement stage 50 should be set to an optimal value according to the amount of charge that the micro object is considered to possess, It is preferable to set to.

  When the movement speed of the fine movement stage 50 is too low, the cantilever 20 drifts (thermal drift) due to the irradiation time of the laser light from the laser displacement meter 30 becoming longer, and the SN ratio of the measurement value deteriorates. When the speed is too high, fine movement stage 50 does not move following the speed setting value. Therefore, the moving speed of fine movement stage 50 is preferably set in the range of 0.1 to 100 um / sec.

  Although the cantilever 20 and the laser displacement meter 30 should be determined according to the amount of charge considered to be held by a minute object, generally, the image force measurement has a more spring constant than the adhesion measurement described later. It is desirable to use a low cantilever and higher resolution laser displacement meter. Specifically, the spring constant of the cantilever is preferably 0.05 N / m or less, more preferably 0.01 N / m or less. The resolution of the laser displacement meter 30 is preferably 10 nm or less, more preferably 1 nm or less. In addition, the cantilever needs to be conductive on its surface and to be grounded.

The image force measured by the above method can be further converted to a charge amount (charge amount). Specifically, for example, conventional techniques (References: Hiroyuki Maruyama, Rie Kiriyama,
Hiroaki Masuda: AFM study of particle electrification by slip and non-slip contact, Proceedings of the Summer Symposium of the Society of Powder Technology, 41 (2005) pp. 67-69) It is possible to calculate (charge amount).

<Determining charging polarity>
A method of determining the charge polarity of the minute object will be described. Here, since the minute object characteristic measurement device 100 is a device that measures “charge polarity” which is one of the characteristics of the minute object, it may be called “a minute object charge polarity measurement device”. Specifically, the holding member 10 holding the minute object positioned at the measurement position is moved in the −Z direction by the three-dimensional moving mechanism to bring the minute object and the cantilever 20 close to each other in the same procedure as the image force measurement. Then, the processing device 60 minutely moves the fine movement stage 50 in the + Z direction to further bring the minute object and the cantilever 20 closer to each other, and operates the charging device to apply a voltage (charge) to the cantilever 20. The processing apparatus 60 applies a positive voltage to the cantilever 20 (adds a positive charge), and when the cantilever 20 is deformed in a direction to be attracted to the minute object, it can be determined that the minute object is negatively charged. When it is deformed in the direction of repulsion against the micro object, it can be determined that the micro object is positively charged. The processing device 60 starts the control of the fine movement stage 50 described above and the acquisition of the measurement value from the laser displacement meter 30 when receiving the processing start request via the operation unit.

  If a negative voltage is applied to the cantilever 20 (negative charge is applied), the determination may be made similarly. If the cantilever 20 is deformed in a direction in which the cantilever 20 is attracted to the minute object, it can be determined that the minute object is positively charged. When the cantilever 20 is deformed in a direction to repel the micro object, it can be determined that the micro object is negatively charged. The distance between the cantilever 20 and the minute object is preferably set to 1 to 5 um. The voltage applied to the cantilever 20 should be determined in accordance with the charge amount of the minute object, and is preferably set to about 0.1 to 3 V in its absolute value.

<Adhesive force measurement>
A method of measuring the adhesion of a minute object will be described. Here, since the micro thing characteristic measuring device 100 is a device which measures "adhesion force" which is one of the characteristics of the micro thing, it may be called "micro thing adhesion measuring device".
As the flow of measurement, the holding member 10 holding the minute object positioned at the measurement position is moved in the −Z direction by the three-dimensional movement mechanism in the same procedure as the image force measurement to bring the minute object and the cantilever 20 close to each other. After that, the processing device 60 minutely moves the fine movement stage 50 in the + Z direction to bring the minute object into contact with the cantilever 20. The processing device 60 starts the control of the fine movement stage 50 described above and the acquisition of the measurement value from the laser displacement meter 30 when receiving the processing start request via the operation unit.

  Whether or not the minute object and the cantilever 20 come into contact can be determined by the measurement value of the laser displacement meter 30 (displacement of the cantilever at the time of contact). The amount of deformation of the cantilever 20 at the time of bringing the minute object into contact with the cantilever 20 depends on the spring constant of the cantilever 20, but is preferably set to about 1 um or less.

  Next, the processing device 60 minutely moves the fine movement stage 50 in the direction in which the minute object and the cantilever 20 separate from each other (−Z direction). Immediately after the movement of the micromotion stage 50, the adhesion between the microobject and the cantilever 20 maintains the contact between the microobject and the cantilever 20. However, if the micromotion stage 50 continues to move, the cantilever 20 The force generated by the warpage is greater than the adhesion between the micro object and the cantilever 20, and the micro object and the cantilever 20 are separated.

  Therefore, the processing apparatus 60 can obtain the adhesion between the micro object and the cantilever 20 by acquiring the force acting on the cantilever 20 when the micro object and the cantilever 20 are separated. When the minute object and the cantilever 20 are separated, the measured value of the laser displacement meter 30 (the amount of deformation of the cantilever 20) is maximized, and the maximum value may be acquired. From the maximum value and the spring constant of the cantilever 20, the adhesion of the minute object can be obtained.

  If the movement speed of the fine movement stage 50 is too low, the cantilever 20 drifts to deteriorate the SN ratio of the measured value. If the movement speed is too high, the fine movement stage 50 follows the speed setting value. It does not move. Therefore, the moving speed of fine movement stage 50 is preferably set in the range of 0.1 to 100 um / sec. The cantilever 20 and the laser displacement meter 30 should be determined according to the adhesion of minute objects, but the spring constant of the cantilever 20 is 0.01 N / m to 1 N / m or less, and the resolution of the laser displacement meter 30 is 100 nm or less It is desirable to have.

  Here, the adhesion between the surface material of the cantilever 20 and the minute object is to be measured. It is not necessary to limit the surface material of the cantilever 20 as long as the adhesion between the minute object held by the holding member 10 and the cantilever 20 is merely compared, but it is easy for the minute object to charge the cantilever 20 In the case of such a material, it is better to use a conductive material on at least the surface of the cantilever 20 and further to ground the cantilever 20. It is preferable to coat the surface of the cantilever 20 with a material having good releasability when evaluating small objects made of a material that may cause contamination of the surface of the cantilever 20 for repeated measurement. .

As described above, the minute object is held by the holding member 10, and the displacement of the cantilever 20 due to the force generated between the minute object and the cantilever 20 facing the minute object when the fine movement stage 50 is moved minutely is measured. Thus, it becomes possible to measure various characteristics of minute objects with high accuracy.
That is, measurement accuracy can be improved.

  In addition, since the micro object characteristic measuring apparatus 100 further includes a processing device 60 that controls the driving device including the fine movement stage 50 and obtains the characteristic of the micro object based on the measurement result of the laser displacement meter 30, the characteristic of the micro object It can be measured automatically.

Further, the cantilever 20 has conductivity and is grounded, and the processing apparatus 60 determines the amount of deformation (warpage) of the cantilever 20 when the minute object held by the holding member 10 and the cantilever 20 are brought close to each other. Find the image power of objects.
In this case, the image force of the minute object can be automatically measured with high accuracy.

In addition, the processing apparatus 60 determines the amount of deformation of the cantilever from the amount of deformation (warpage) of the cantilever when the minute object and the cantilever 20 are separated from the state where the minute object held by the holding member 10 contacts the cantilever 20. Ask for a fit.
In this case, the adhesion of the minute object can be measured automatically with high accuracy.

  Further, since the cantilever 20 has conductivity and is grounded, charge accumulation on the minute object and the cantilever 20 can be prevented even when contact between the minute object and the cantilever 20 is repeated in adhesion measurement. . As a result, when measuring the adhesion, the image force of the minute object can be made almost zero, and the measurement accuracy of the adhesion can be further improved.

  In the adhesion measurement, the holding member 10 may have conductivity and may be grounded instead of or in addition to the conductivity of the cantilever 20 and being grounded. Also in this case, the image force of the minute object at the time of the adhesion measurement can be made almost zero, and the measurement accuracy of the adhesion can be further improved.

The minute object characteristic measurement apparatus 100 further includes a charging device for charging the cantilever 20 positively or negatively, and the processing device 60 is a cantilever when the minute object held by the holding member 10 and the cantilever 20 are brought close to each other. From the deformation direction (warpage direction) of 20, the charging polarity of the minute object is determined.
In this case, it is possible to automatically measure (determine) the charging polarity of the minute object with high accuracy.

  In addition, since the laser displacement meter 30 is used as a measuring device for measuring the displacement of the cantilever 20, the distance can be measured and miniaturization can be achieved.

  Further, since the driving device including fine movement stage 50 can integrally drive cantilever 20 and laser displacement meter 30 in the approaching direction and the separating direction, displacement due to deformation (warpage) of cantilever 20 can be accurately performed. It can be measured.

  In addition, since the cantilever 20 and the laser displacement meter 30 are installed on the rigid fine movement stage 50 via the fixing jig 40, they can move minutely and smoothly and are not easily affected by noise due to vibration or the like. The displacement due to deformation can be measured more accurately.

  In addition, by synchronizing the driving by the driving device (the movement of the fine movement stage 50) and the measurement by the laser displacement meter 30, it is possible to measure the mirror image force, adhesion, and charging polarity of minute objects in a short time. The influence of drift can be reduced.

  Further, after the minute object measuring apparatus 100 holds (collects) the holding member 10 at a position (sampling position) where the minute object does not face the cantilever 20, the holding member 10 for holding the minute object is the cantilever and the cantilever It further comprises a three-dimensional moving mechanism (moving means) for moving it to a position (measurement position) in which 20 and 20 face each other.

In this case, it is possible to smoothly shift from the collection of the minute object to the characteristic measurement, and the evaluation of the minute object can be realized in a short time.
Also, the cantilever 20 is a cantilever for an atomic force microscope.

  In this case, since the surface of the cantilever 20 has high smoothness, it is possible to suppress the change in the contact area between the minute object and the cantilever for each measurement. In addition, when optically measuring the amount of deformation of the cantilever 20, the light that strikes the cantilever 20 is detected without scattering and is maintained while maintaining the straightness, so that the measurement accuracy can be improved.

  In addition, in the case where the holding member 10 has a pair of arms capable of gripping a minute object, any one minute object (one particle) can be reliably collected.

  In addition, in the case where the holding member 10 can adsorb a minute object, the holding member 10 can collect any one minute object (one particle) in a state in which the load applied to the minute object is reduced.

Second Embodiment (Measurement of Electric Resistance)
Below, 2nd Embodiment is demonstrated based on FIG. 5 about the structure of measurement of an electrical resistance. The minute object characteristic measuring apparatus 200 according to the second embodiment is an apparatus for measuring the electric characteristics (electric resistance and dielectric constant) of the minute object, and may be referred to as “a minute object electrical characteristic measuring apparatus”.

  The structure which measures the electrical resistance of a micro thing using the micro thing characteristic measuring apparatus 200 of 2nd Embodiment is typically shown by FIG. In FIG. 5, the fine movement stage 50, the fixing jig 40, and the laser displacement meter 30 are not shown.

  More specifically, as shown in FIG. 5, in the microparticle characteristic measuring apparatus 200, the holding member 10 having conductivity, the cantilever 20 having conductivity, and the holding member 10 and the cantilever 20 are separately connected to both poles. A DC power supply for applying a DC voltage to the micro object, and an ammeter for measuring the current flowing to the micro object when the holding member 10 and the cantilever 20 are conducted via the micro object. It constitutes a series circuit. As described above, in the minute object characteristic measurement apparatus 200, the holding member 10 having conductivity and the cantilever 20 can be used as an electrode.

  As a measurement method other than the configuration shown in FIG. 5, a method of inserting a reference resistance in the measurement circuit and measuring the voltage drop of the reference resistance using a voltmeter, or a lock-in amplifier for extracting only a specific frequency component is provided. There is a method of measuring the current by applying an alternating voltage.

  In FIG. 5, the holding member 10 is connected to the hi terminal (positive electrode) of the power supply, and the cantilever 20 is connected to the lo terminal (negative electrode) of the power supply.

  In order to use the holding member 10 as an electrode, it is necessary to ensure conduction (conductivity) at least from the contact surface with the minute object to the connection point with the power source. As a specific numerical value for conduction, it is desirable that the resistance value of the minute object to be measured be 1/10 or less. In the case where the holding member to be used does not normally obtain conductivity (in the case where the holding member does not have conductivity), for example, a method of forming the surface of the holding member using gold, copper, tungsten, etc. Conductivity (conductivity) is secured by a method of forming a microelectrode using a deposition function by a beam or the like.

  As the flow of measurement, the holding member 10 holding the minute object positioned at the measurement position is moved in the −Z direction by the three-dimensional movement mechanism in the same procedure as the image force measurement to bring the minute object and the cantilever 20 close to each other. After that, the processing device 60 minutely moves the fine movement stage 50 in the + Z direction to bring the minute object into contact with the cantilever 20. As a result, it is possible to quickly construct a circuit that allows the holding member 10 and the cantilever 20 to be conducted through the minute object. The processing device 60 determines whether or not the minute object and the cantilever 20 come in contact with each other based on the measurement value of the laser displacement meter 30 (the amount of deformation of the cantilever 20 at the time of contact). The amount of deformation of the cantilever 20 at the time of bringing the minute object into contact with the cantilever 20 depends on the spring constant of the cantilever 20, but is preferably set to about 1 um or less. The processing device 60 starts the control of the fine movement stage 50 described above and the acquisition of the measurement value from the laser displacement meter 30 when receiving the processing start request via the operation unit.

  The contact state (contact pressure) of the minute object and the electrode can be managed with high accuracy by using a cantilever for one electrode. There are two reasons why the contact state can be managed accurately. The first reason is that by measuring the amount of deformation of the cantilever 20 with the laser displacement meter 30, the pressure applied to the minute object can be managed. For example, if the configuration is based on a cantilever having a spring constant of 0.01 N / m and a laser displacement meter 30 having a resolution of 10 nm, the pressure applied to a minute object can be managed in units of 0.1 nN. The second reason is that the surface of the cantilever 20 has high smoothness. Thereby, it is possible to minimize the change in the contact area with the minute object due to the surface unevenness for each measurement.

  As described above, after the holding member 10 and the cantilever 20 are electrically connected via the minute object, the processing device 60 applies a voltage to the minute object by the DC power supply, and causes the current value flowing to the minute object to be an ammeter And the electrical resistance can be determined from Ohm's law.

  The upper limit of the voltage applied to the minute object is desirably about 100 V in order to avoid discharge between the electrodes. As for current measurement, in order to avoid the influence of input inrush current, it is desirable to stand for about 1 minute immediately after voltage application and start reading. Also, in order to obtain accurate measurement results, change the value of applied voltage in one measurement, read the change in current value accompanying it, and obtain the resistance value by linear regression against Ohm's law. Is desirable.

<Permittivity measurement>
When measuring the dielectric constant of the minute object, an alternating current power supply may be used in place of the direct current power supply in the configuration for measuring the electric resistance of the minute object characteristic measuring apparatus 200. By using an alternating current power supply, it is possible to measure the frequency response of the current flowing to the minute object and obtain the impedance. Further, the dielectric constant can be obtained by obtaining a capacitor from the impedance.

  FIG. 6 shows a configuration for measuring the dielectric constant of a micro object using the micro object characteristic measuring apparatus 200. In FIG. 6, the fine movement stage 50, the fixing jig 40, and the laser displacement meter 30 are not shown. 6, in the configuration shown in FIG. 5, the DC power supply is replaced with an AC power supply, and the holding member 10 and the cantilever 20 are connected via a voltmeter. Therefore, it is possible to measure an impedance by applying an alternating voltage to the minute object and measuring the current and voltage flowing to the minute object. Further, in the configuration shown in FIG. 6, in addition to the dielectric constant, the electrical resistance can also be measured.

  The minute object characteristic measurement apparatus 200 according to the second embodiment described above includes a holding member 10 having conductivity capable of holding a minute object, and a cantilever 20 having conductivity which faces the minute object held by the holding member 10. The driving device includes a fine movement stage 50 capable of driving the cantilever 20 in the direction in which the minute object held by the holding member 10 and the cantilever 20 approach and separate, and the holding member 10 and the cantilever 20 have both poles individually. The power supply connected and the ammeter which measure the electric current which flows into a micro thing when the holding member 10 and the cantilever 20 are conduct | electrically_connecting via the micro thing are provided.

  In this case, a minute object is held by the holding member 10, the fine movement stage 50 is moved minutely, and the minute object is brought into contact with the cantilever 20 opposed to the minute object so that a current flows through the minute object and the current is measured. , It becomes possible to measure the electrical characteristics of the minute object.

In this case, due to the elastic force of the cantilever 20, the minute object held by the holding member can be reliably brought into contact with the cantilever 20.
As a result, measurement accuracy can be improved.

  Further, since the micro object characteristic measurement device 200 further includes the laser displacement meter 30 that measures the displacement of the cantilever 20, the contact state (contact pressure) of the micro object and the cantilever 20 can be precisely managed.

In addition, the micro object characteristic measurement device 200 further includes a processing device that obtains the characteristics of the micro object from the measurement result of the ammeter when the micro object held by the holding member 10 is in contact with the cantilever 20.
In this case, the characteristics (electrical characteristics) of the minute object can be automatically measured with high accuracy.

  Further, since the power source is a direct current power source, and the characteristics of the minute object to be measured by the minute object characteristic measurement apparatus 200 are the electric resistance of the minute object, the electric resistance can be measured simply and rapidly with high accuracy. it can.

  The power source is an AC power source, and further includes a voltmeter for measuring a voltage applied to the micro object when the holding member 10 and the cantilever 20 are conducted through the micro object, and the characteristics of the micro object are Since at least one of the dielectric constant and the electrical resistance of the minute object, at least one of the dielectric constant and the electrical resistance can be measured easily and quickly with high accuracy.

  In addition, since it is possible to perform measurement while holding only one particle between the holding member 10 and the cantilever 20, it is possible to stably measure the inherent electrical characteristics (electrical resistance and dielectric constant) of the one particle. Can be measured.

  On the other hand, when measuring the electrical characteristics of a group of minute objects by holding the group of minute objects containing a plurality of minute objects between a pair of electrodes, the flowability of the minute objects makes the group of minute objects and each electrode The contact state changes, and stable and high-accuracy measurement can not be performed. That is, in this case, the measurement accuracy is influenced by the filling rate of the minute object, the molding state, and the like.

  The minute object characteristic measurement apparatus 200 includes the laser displacement meter 30 that measures the displacement of the cantilever 20, but may not have this. In this case, it is necessary to rely on visual observation through a microscope or the like for contacting the micro object and the cantilever, but it is sufficient to measure the electrical characteristics (electrical resistance and dielectric constant) of the micro object. It is possible.

  When the holding member 10 has a pair of arms capable of gripping a minute object, each arm and the cantilever 20 may be electrically connected through the minute object. Alternatively, one of the pair of arms and the cantilever 20 may be electrically connected through the minute object, and the other may not be electrically connected with the cantilever 20 through the minute object (see FIGS. 5 and 6). In this case, since it is possible to reduce the leakage current to the arm not used for measuring the electrical resistance of the minute object, the measurement accuracy can be further improved.

  By the way, in order for researchers and engineers to carry out quality evaluation and further mechanism analysis, it is often insufficient to evaluate one characteristic value of a microscopic object. On the other hand, if a plurality of devices are introduced according to the analysis content, the device introduction cost and the maintenance cost become enormous. In addition, when trying to measure multiple characteristics for the same small object, it is necessary to move the same sample of small size between multiple measuring devices, which requires advanced positioning technology and evaluation. Is likely to take longer.

  As can be understood from the description of the first and second embodiments, the minute object characteristic measuring apparatus according to the present invention appropriately changes the configuration according to the contents of measurement to obtain a plurality of characteristics (for example, adhesion force, image force, Charge polarity, electrical resistance, dielectric constant, etc.) can be measured. In the first and second embodiments, one cantilever can be used to measure a plurality of properties of a minute object, but the suitable cantilever differs depending on the measurement content.

  Therefore, if the minute object characteristic measurement apparatus is configured to hold a plurality of cantilevers, the plurality of characteristics can be measured in a short time without replacing the cantilevers.

Third Embodiment (a plurality of cantilevers)
As an example, a plurality of cantilevers are held and positions (here, positions in the Y-axis direction) as in the microscopic object characteristic measurement device 300 of the third embodiment shown in FIGS. 7A and 7B. A plurality of measurements can be performed more efficiently by using a holding jig (cantilever holder) capable of changing. In FIGS. 7A and 7B, the fine movement stage 50, the laser displacement meter 30, and the processing device 60 are not shown. Specifically, the conductivity measurement cantilever and the adhesion measurement cantilever are provided with conductivity and grounding function, and the electric resistance / dielectric constant measurement cantilever is provided with a power supply, an ammeter, and a voltmeter. Make a circuit including the If such a holding jig is used, the position of the cantilever can be changed simply by changing the position of the holding jig, and the measurement contents can be changed in a short time.

  Further, as a modification of the third embodiment, it is also useful to provide a voltage application function (charging device) to a cantilever for charge amount measurement in order to make it possible to determine the charge polarity of the minute object. Further, instead of moving the holding jig in the Y-axis direction, the holding member may be moved in the Y-axis direction. When only the electrical resistance is to be measured, a DC power supply may be used instead of the AC power supply in FIGS. 7A and 7B. Moreover, the measurement content which each cantilever bears can be suitably changed not only in the example shown by FIG. 7 (A) and FIG. 7 (B). For example, the image measurement and the adhesion measurement may be carried by the same cantilever, or the electric resistance measurement and the permittivity measurement may be carried by different cantilevers. Also, a cantilever for charge polarity measurement may be added.

  The minute object characteristic measurement apparatus 300 according to the third embodiment described above integrally includes a holding member 10 capable of holding a minute object, and a plurality of cantilevers individually capable of individually facing the minute object held by the holding member 10. A cantilever device including the laser device, a laser displacement meter 30 for measuring displacement of the cantilever facing the minute object held by the holding member 10 among the plurality of cantilevers, one of the holding member 10 for holding the minute object and the cantilever device The micro object held by the holding member 10 is moved to a position where any one of the plurality of cantilevers is opposed to each other, and the micro object held by the holding member 10 and the one cantilever approach and separate And a driving device including a fine movement stage 50 that can be driven in the direction.

  In this case, a cantilever suitable for the measurement content (for example, the image force and adhesion force of the minute object, charging polarity) can be selected simply and quickly and used, and the measurement time for measuring a plurality of characteristics (measurement content) Can be shortened.

  On the other hand, when trying to measure a plurality of characteristics for the same minute object, it is necessary to move the same sample of a minute size between a plurality of measuring devices, which requires a high-level localization technique, and evaluation Is likely to take longer.

  The holding member 10 is conductive, and the plurality of cantilevers includes a conductive cantilever, and the power supply in which the poles are individually connected to the holding member 10 and the conductive cantilever, and the conductive cantilever and And an ammeter for measuring a current flowing between the cantilever and the holding member when the holding member is electrically connected via the minute object.

  In this case, a cantilever suitable for the measurement content (for example, the electrical resistance of a minute object) can be selected simply and quickly and the measurement time can be shortened.

  In addition, since the micro object characteristic measurement apparatus 300 further includes a processing apparatus that can control the drive including the fine movement stage 50 and obtain the characteristic of the micro object based on the measurement result of the laser displacement meter 30, If necessary, the characteristics (image force, adhesion, charge polarity) of the minute object can be automatically measured with high precision.

  In addition, the minute object characteristic measuring apparatus 300 obtains the characteristics of the minute object based on the measurement result of the ammeter when the minute object held by the holding member 10 is in contact with the conductive cantilever 20. As a result, it is possible to automatically and accurately measure the characteristics (electrical resistance) of small objects as needed.

  Further, the power source is an AC power source, and the minute object characteristic measuring apparatus 300 measures a voltage applied to the minute object when the conductive cantilever 20 and the holding member 10 are electrically connected via the minute object. The processing apparatus 60 further includes a voltmeter on the basis of the measurement results of the ammeter and the voltmeter when the minute object held by the holding member 10 is in contact with the conductive cantilever 20. Since it is possible to obtain the electrical characteristics of the above, it is possible to automatically and accurately measure the characteristics of the minute object (electrical resistance and dielectric constant) as needed.

  In addition, since the processing apparatus can change grounding conditions and voltage application conditions for each cantilever, it can cope with many measurement contents with a small number of cantilevers, and can quickly change the measurement contents.

  In the second and third embodiments, the minute object is held by the holding member, but instead, the minute object may be fixed (for example, adhered) to a conductive member. Then, the micro object fixed to the conductive member may be brought into contact with the cantilever, and the electric resistance and the dielectric constant of the micro object may be measured as in the second and third embodiments.

  In the first embodiment, as shown in FIG. 1, the fine movement stage 50, the laser displacement meter 30, and the cantilever 20 are integrally provided. Although the configuration of FIG. 1 is a configuration that is less susceptible to the influence of noise due to vibration, for example, when the configuration of FIG. 1 can not be realized due to cost or manufacturing convenience, etc. Alternatively, the holding member 10 and the fine movement stage may be integrally provided, and the holding member 10 may be minutely moved together with the fine movement stage 50. Furthermore, as in the minute object characteristic measurement apparatus according to the second modification, the displacement gauge fixing jig which is a fixing jig of the laser displacement meter 30 and the cantilever fixing jig which is a fixing jig of the cantilever 20 are separately provided. Alternatively, only the cantilever fixing jig may be minutely moved along with the fine movement stage.

  However, in the case of the configuration of the second modification, the cantilever 20 moves relative to the laser displacement meter 30 with the movement of the fine movement stage 50 even in a state where no force acts on the cantilever 20 and no deformation occurs. The measured value of the laser displacement meter 30 changes. Therefore, it is necessary to determine the mirror image force and the adhesive force after determining the displacement due to the deformation of the cantilever by the difference between the measurement value of the laser displacement meter 30 and the movement amount of the fine movement stage 50 (movement amount of the cantilever 20).

  Also, the means for detecting the displacement of the cantilever does not necessarily have to measure the distance directly like a laser displacement meter. For example, a minute object characteristic measuring apparatus irradiates a cantilever with a laser beam from a laser light source, and detects the reflected light with a two-divided detector (for example, a two-divided photodiode or a two-divided phototransistor) having two light receiving regions. It is also possible to adopt This is a method of detecting the change in the advancing angle of the reflected light due to the deformation of the cantilever 20 at the position of the reflected light on the two-divided detector. That is, when the cantilever 20 is warped, the central position of the laser beam striking the two-divided detector is shifted, and the difference between the outputs from the two light receiving regions changes. The amount of warpage of the cantilever can be calculated from this change. This is the same as an optical lever system generally used in an atomic force microscope, but can also be adopted in the cantilever displacement measurement of the present invention. A fixture with a long height (thickness) may be used for convenience of the installation size of the 2-divided detector, or a configuration in which the fine movement stage, the laser displacement meter 30, and the cantilever 20 are not integral may be adopted. Not necessarily limited to these configurations.

  That is, this minute object characteristic measuring apparatus includes a light source for emitting laser light toward a cantilever, and a photodetector including two light receiving areas for detecting light emitted from the light source and reflected by the cantilever. Therefore, the measurement accuracy can be improved compared to, for example, the case of using a laser displacement meter.

  Although the two-divided detector is used as the above-described light detector, it is essential that the detector (having two or more light-receiving areas) (more preferably, a photodetector) is necessary.

Fourth Embodiment
Next, the minute object characteristic measurement devices 800a to 800e according to the first to fifth embodiments of the fourth embodiment will be described with reference to FIGS. The minute object characteristic measurement device according to each example of the fourth embodiment includes a plurality of holding members capable of holding minute objects.

Example 1
In the minute object characteristic measurement apparatus 800a of the first embodiment, as shown in FIG. 8, the two holding members 1 and 2 face in the horizontal direction (for example, the Y-axis direction) below the optical microscope lens as the observation lens. It is possible.

  More specifically, the two holding members 1 and 2 are provided such that the longitudinal direction is substantially parallel to the Y-axis in a state in which the end portions holding the micro objects face each other when viewed from the Z-axis direction There is.

  The holding operation and the holding releasing operation of the minute object by the holding member can be performed by the operator (experimenter) through the operation unit.

  The holding member 1 is drivable by a drive system 1 including a support member 1 and drive means 1. The holding member 2 is drivable by a drive system 2 including a support member 2 and drive means 2.

  That is, the drive systems 1 and 2 constitute a “drive system” capable of independently driving the two holding members 1 and 2.

  The holding member 1 is supported by the support member 1 via the driving means 1. The holding member 2 is supported by the support member 2 via the drive means 2. The driving means 1 can drive the holding member 1 in the Z-axis direction (vertical direction) with respect to the support member 1. The driving means 2 can drive the holding member 2 with respect to the support member 2 in the Z-axis direction. That is, by operating the driving means 1 and 2, the holding members 1 and 2 can be moved up and down independently.

  As each driving means, it is essential that the holding member can be moved up and down. For example, an elevation mechanism including a micrometer head, an elevation mechanism including a motor, an elevation mechanism including a solenoid, and a fine movement stage using a piezo element as an actuator Etc. can be used. Here, each drive means is operable by the operator via the operation unit. Hereinafter, each drive means is also referred to as "lifting drive means".

  As each holding member, for example, micro / nano-grippers with different opening widths between arms and micro / nano-tweezers are suitable.

  Here, usually, the size of the minute object is not constant, but varies within a certain range.

  If the opening width between the arms is large, large particles and foreign matter can be held, but since it is difficult to adjust the opening width between the arms, it becomes difficult to hold small particles and foreign matter without damage.

  On the other hand, if the opening width between the arms is small, small particles and foreign substances can be held, but particles and foreign substances larger than the opening width between the arms can not be held.

  That is, a single holding member can not cope with variations in the size of minute objects. Then, although it is possible to exchange a holding member according to the size of a minute thing, measurement efficiency will fall by this.

  Therefore, by providing micro / nano-grippers with different opening widths between arms and micro / nano-tweezers as holding members 1 and 2 as the holding members 1 and 2, the size of the minute object can be obtained without replacing the holding members. It is possible to cope with the variation and proceed smoothly with the measurement.

  Here, the holding member 1 has a small opening width, and the holding member 2 has a large opening width.

  In FIG. 9A, the relationship between the size distribution of the minute objects (the number of minute objects per size) and the opening width of the holding member 1 is shown as an example. It can be understood from FIG. 9A that the holding member 1 can cope with the low to medium size of the size distribution of the minute object (see the hatching area in FIG. 9A).

  In FIG. 9B, the relationship between the size distribution of the minute objects and the opening width of the holding members 1 and 2 is shown as an example. It can be understood from FIG. 9B that the holding member 2 can cope with the medium to large size of the size distribution of the minute objects (refer to the hatching region in the right half of FIG. 9B).

  Here, in the case where a plurality of holding members are mounted on the micro object characteristic measuring device, when the micro objects are collected from the substrate, the holding members used for collecting the micro objects and the non-used holding members scatter the micro objects. There is a concern that it may come in contact with the substrate being damaged. In particular, in the case of a minute object characteristic measuring apparatus, since the purpose is to hold and measure micron-sized minute objects, a high magnification observation system is mounted. For this reason, it is assumed that the observation visual field is narrow and the plurality of holding members do not enter the same visual field. In this case, since the holding member which is not used is out of the visual field of the experimenter, the state can not be confirmed, and even if the tip of the holding member contacts the substrate surface and it is likely to be damaged, it may not be noticed.

  Therefore, when collecting minute objects from the substrate (on the sampling area), one of the holding members 1 and 2 that matches the size of the minute object to be collected is used, and the other holding member is In order to prevent damage due to contact with the substrate, it is preferable to use a lifting drive means to retract to a height position away from the substrate.

  In addition, the holding members 1 and 2 may be micro / nano grippers or micro / nano tweezers different in surface material.

  For example, the holding member 1 is a micro / nano-gripper or micro / nano tweezers in which the surface layer is formed of a conductive material for measurement of electrical resistance and permittivity, and the holding member 2 is a surface layer of dielectric for measurement of charge amount and adhesion. By using the formed micro / nano grippers or micro / nano tweezers, it is possible to smoothly shift from one measurement to another without exchanging the micro / nano grippers or the micro / nano tweezers between measurements.

  In particular, when performing measurement including charge amount measurement (image force measurement), the charge amount decays with time, so it is very beneficial not to generate the micro / nano gripper and micro / nano tweezers exchange time in this way It is.

  Further, in addition to enabling each holding member to be independently moved in the Z-axis direction by the elevation driving means, it is possible to move along the XY plane (horizontal plane) and to be rotatable around the Z axis, and By making at least one of the holding members 1 and 2 rotatable about an axis (e.g., Y axis) parallel to the longitudinal direction, the variation of the measurement method can be expanded.

  Therefore, as an example, in addition to the elevation driving means provided on the supporting member, each driving system is a horizontal movement driving means capable of moving the supporting member supporting the corresponding holding member along the XY plane, It has a drive means for rotation around the Z axis which can rotate the support member around the Z axis, and a drive means for rotation around the Y axis which can rotate the holding member around the Y axis.

  Here, the fixed portion of the Z-axis rotation drive means may be attached to the movable portion of the horizontal movement drive means, and the support member may be attached to the Z-axis rotation drive means, or the Z-axis rotation means. The fixed part of the horizontal movement drive means may be attached to the movable part of the drive means, and the support member may be attached to the movable part of the horizontal movement drive means.

  In addition, the fixed part of the elevating drive means is attached to the support member, the fixed part of the drive means for rotation around the Y axis is attached to the movable part of the drive means for elevation, and held by the movable part of the drive means for rotation around the Y axis. A member is attached.

  Examples of the horizontal movement drive means include a linear drive including a ball screw and a rack and pinion mechanism. Examples of the drive unit for rotation around the Z axis and the drive unit for rotation around the Y axis include a rotation drive apparatus including a motor.

  Further, in addition to the lifting and lowering drive means, the horizontal moving drive means, the driving means for rotating around the Z axis, and the driving means for rotating around the Y axis can be operated by the operator via the operation unit. That is, the drive system including the drive systems 1 and 2 can be operated via the operation unit. The configuration of the drive system can be changed as appropriate.

Specifically, the following two measurement methods become possible.
The first is that measurements of different characteristics can be continuously performed on the same minute object.

  For example, the holding member 1 is a micro-gripper (hereinafter also referred to as a conductive micro-gripper) in which the surface layer is formed of a conductive material for measuring electric resistance and dielectric constant, and the holding member 2 is a surface layer for measuring charge amount and adhesion. A micro-gripper formed of a dielectric (hereinafter also referred to as an insulating micro-gripper) is used.

  Then, as shown in FIG. 10, as in the third embodiment, the charge amount measuring cantilever, the adhesion force measuring cantilever, and the electrical resistance / dielectric constant measurement cantilever held by the cantilever holder are provided. Here, the holding member 2, the charge amount measurement cantilever, and the adhesion force measurement cantilever are grounded. An ammeter and a power source are connected between the holding member 1 and the electrical resistance / dielectric constant measurement cantilever.

  In this case, for example, after holding the minute object with the conductive microgripper and measuring the electric resistance and the dielectric constant, as shown in FIG. 11A to FIG. By switching from the gripper to the insulating microgripper, it is possible to measure the charge amount and the adhesion of the minute object. Note that, by operating the drive system, the conductive micro-gripper holding micro-objects is moved between the position where the micro-objects face the cantilever and the position where the micro-objects retract from the position; Insulating microgrippers can be opposed.

  Here, the operation of changing the hand of the minute object from the conductive microgripper to the insulating microgripper will be described. The operator performs the switching operation by appropriately operating the drive unit for rotation around the Y axis, the drive unit for horizontal movement, and the micro gripper through the operation unit while the operator looks into the optical microscope lens from above.

  The conductive micro-gripper and the insulating micro-gripper opposite to each other in the Y-axis direction are initially in a reference state in which the opening direction of the arms is horizontal (here, the X-axis direction). In the state (see FIG. 11 (A)) in which the micro thing is held (nipped) by the conductive micro-gripper, the insulating micro-gripper is rotated from the reference state (see FIG. 11 (B)) and held by the conductive micro-gripper The small particle and the insulating micro-gripper are brought close to each other in the Y-axis direction, and the region different from the part of the particle which is held by the conductive micro-gripper is held by the insulating micro-gripper (FIG. 11 (C )reference). In this state, holding of the micro object by the conductive micro gripper is released, and the insulating micro gripper and the conductive micro gripper, which hold the micro object, are separated in the Y-axis direction (see FIG. 11D). The insulating micro-gripper holding the object is returned to the reference state (see FIG. 11E). Note that, instead of or in addition to rotating the insulating micro-gripper, the conductive micro-gripper holding micro objects may be rotated.

  In addition, when the electric resistance / dielectric constant measurement is performed after the charge amount measurement or the adhesive force measurement, the holding work of the minute objects from the insulating microgripper to the conductive microgripper can be performed in the same manner.

  The second is that a plurality of aggregated micro-particles can be separated using a plurality of holding members, and characteristic measurement can be performed on each separated micro-particle.

  Specifically, as shown in FIGS. 12A to 12E, an aggregate (hereinafter also referred to simply as “aggregate”) in which a plurality of (for example, two) minute substances are aggregated is After sampling with a microgripper, at least one microparticle of the aggregate gripped (nipped) by the one microgripper is gripped by another microgripper, and the other microgripper is operated to coagulate it. You can break up the collection. By separating the aggregates into minute units by such gripping and operation, it is possible to perform measurement according to the purpose for each minute object. In addition, what is necessary is just to repeat the said holding | grip and operation, when an aggregate is comprised with three or more micro things.

  The separation operation of the aggregates will be described in detail. This separation operation is performed by appropriately operating the drive unit for rotation around the Y axis, the drive unit for horizontal movement, and the micro gripper through the operation unit while the operator looks into the optical microscope lens from above. Here, an aggregate in which two minute objects (one and the other minute objects) are aggregated will be described as an example.

  One and the other micro grippers facing in the Y-axis direction are initially in the reference state in which the opening direction of the arm is horizontal (here, the X-axis direction). In a state in which one micro gripper grips one micro object of the aggregate (see FIG. 12A), the other micro gripper is rotated from the reference state (see FIG. 12 B), one micro gripper The aggregate held on top of one another and the other micro grippers are brought close to each other in the Y-axis direction, and the other particles of the aggregates (the particles not held by one macro gripper) are held by the other micro grippers. (See FIG. 12C). In this state, one micro gripper holding one micro object and another micro gripper holding another micro object are separated in the Y-axis direction to separate one and the other micro object (FIG. 12 (D ), Return the other micro grippers holding other micro objects to the reference state (see FIG. 12 (E)). Note that, instead of or in addition to rotating other micro-grippers, one micro-gripper holding micro objects may be rotated.

Example 2
In the minute object characteristic measurement device 800b of the second embodiment, as shown in FIG. 13, the two holding members 1 and 2 are provided to be aligned in the X axis direction at least when viewed from the Z axis direction. Here, the holding member 2, the charge amount measurement cantilever, and the adhesion force measurement cantilever are grounded. An ammeter and a power source are connected between the holding member 1 and the electrical resistance / dielectric constant measurement cantilever.

  More specifically, the two holding members 1 and 2 have at least the X axis so that the longitudinal direction is substantially parallel to the Y axis in a state in which the tips holding the minute objects face the same direction (here, -X direction). It is spaced apart in the direction.

  The second embodiment is also effective in that the characteristic measurement of a minute object with a wide size distribution and the plurality of different characteristic measurements can be efficiently performed.

  When the holding members 1 and 2 are disposed to face each other as in the first embodiment, the space for installing each holding member and each drive system is increased. However, in the second embodiment, even a narrower space is provided. Installation becomes possible, and miniaturization of the entire device can be achieved.

  Further, as shown in FIGS. 14A and 14B, by sharing one supporting member with two holding members 1 and 2, the number of parts (specifically, the supporting member, the support) It is also possible to reduce the number of drive means for driving the members in the horizontal direction.

Example 3
In the minute object characteristic measurement apparatus 800c according to the third embodiment, as shown in FIG. 15, the two holding members 1 and 2 have axes parallel to the longitudinal direction orthogonal to each other when viewed at least from the Z axis direction Provided). Here, the holding member 2, the charge amount measurement cantilever, and the adhesion force measurement cantilever are grounded. An ammeter and a power source are connected between the holding member 1 and the electrical resistance / dielectric constant measurement cantilever.

  More specifically, when viewed from the Z-axis direction, the two holding members 1 and 2 have substantially parallel axes parallel to the longitudinal direction with the tips holding the minute objects directed to the same place in the XY plane. It is arranged as.

  In the third embodiment, the installation space of each holding member and each drive system can be reduced, and it is also possible to separate aggregates in which a plurality of minute objects are aggregated into minute units (FIGS. 16A to 16). (C)). The left and right views of FIGS. 16A to 16C are views of the same state viewed from different directions.

  The separation operation of aggregates in Example 3 will be described. This separation operation is performed by appropriately operating the horizontal movement drive means, the elevation drive means, and the micro gripper while the operator looks into the optical microscope lens from above. Here, an aggregate in which two minute objects (one and the other minute objects) are aggregated will be described as an example.

  One and the other micro grippers whose axes parallel to the longitudinal direction are orthogonal to each other are initially in the reference state in which the opening direction of the arm is horizontal. The aggregate in which one micro gripper is held by one micro gripper and the tip of the other micro gripper is positioned at the top and bottom (see 16 (A)), and the other microparticles of the aggregate (one micro The micro object (not held by the gripper) and the other micro gripper are brought close to each other in the Z-axis direction, and the other micro gripper holds the other object (see FIG. 16B). Then, one micro gripper for holding one micro object and another micro gripper for holding another micro object are separated in the Z-axis direction (see FIG. 16C).

Example 4
As shown in FIG. 17, the micro object characteristic measurement device 800 d according to the fourth embodiment includes three micro grippers 1 to 3 each capable of holding a micro object. Here, the micro-grippers 1 and 2, the charge amount measurement cantilever, and the adhesion force measurement cantilever are grounded. An ammeter and a power supply are connected between the micro gripper 3 and the cantilever for measuring the electrical resistance / dielectric constant.

  More specifically, the minute object property measuring apparatus 800d comprises two insulating microgrippers 1 and 2 having different opening widths for charge amount and adhesion measurement, and a conductive microgripper 3 for electric resistance and dielectric constant measurement. Have.

  Here, the insulating micro-gripper 1 and the conductive micro-gripper 3 are provided to face in the Y-axis direction, and the insulating micro-gripper 2 is between the insulating micro-gripper 1 and the conductive micro-gripper 3 in the Y-axis direction. Are provided substantially parallel to the X-axis direction.

  In this case, the aggregates can be separated in the same manner as in Example 3 using the insulating microgrippers 1 and 2 or using the insulating microgripper 2 and the conductive microgripper 3, and the insulating microgripper 1 and Holding of the minute objects can be carried out in the same manner as in Example 1 using conductive microgripper 3, and separation of aggregates in the manner of Example 1 using insulating microgripper 1 and conductive microgripper 3 be able to.

  As a result, it is possible to continuously carry out measurement of charge amount / adhesion and electric resistance / dielectric constant measurement for each minute object even for an aggregate in which a plurality of minute objects with a wide size distribution are aggregated. Become.

Example 5
As shown in FIG. 18, the micro object characteristic measurement device 800 e of the fifth embodiment includes four micro grippers 1 to 4 each capable of holding a micro object.

  The micro grippers 1 and 2 are provided with two insulating micro grippers 1 and 2 with different opening widths and two conductive micro grippers 3 and 4 with different opening widths.

  Here, the insulating micro-gripper 1 and the conductive micro-gripper 4 are provided to face each other in the Y-axis direction, and the insulating micro-gripper 2 and the conductive micro-gripper 3 are provided to be aligned in the Y-axis direction. ing.

  In this case, the aggregates can be separated in the same manner as in Example 3 by using micro grippers 1 and 2 or by using micro grippers 3 and 4, and by using micro grippers 1 and 4 as in Example 1. The minute objects can be exchanged, and the aggregates can be separated in the same manner as in Example 1 using the micro grippers 1 and 4. Also, the micro grippers 2 and 3 can be used as in the second embodiment.

  As a result, it is possible to continuously carry out measurement of charge amount / adhesion and electric resistance / dielectric constant measurement for each minute object even for an aggregate in which a plurality of minute objects with a wide size distribution are aggregated. Become.

  Also in the fourth embodiment, a series of measurement operations other than using a plurality of holding members can be performed in the same manner as each of the embodiments and the modifications.

  In the fourth embodiment described above, the measurement efficiency can be improved and the device can be miniaturized by setting the number and the layout (arrangement) of the holding members in consideration of a plurality of measurement contents. In addition, the said Examples 1-5 are an example, Comprising: The number and layout of a holding member are changeable suitably. For example, the number of holding members may be five or more, and a plurality of holding members may be arranged in the Z-axis direction.

  Further, in the fourth embodiment, the micro-gripper as the holding member is mainly described as an example, but the holding members other than the micro-gripper (for example, the holding member capable of suctioning a minute object etc.) are also Examples 1-5. The same effect can be obtained by installing and using in the same manner.

  In the fourth embodiment, the measurement (determination) of the charging polarity of the minute object is not mentioned, but the procedure described in the first embodiment using the minute object characteristic measuring devices 800a to 800e of the first to fifth embodiments. It is also possible to measure the charge polarity of minute objects.

  The minute object characteristic measurement devices 800a to 800e (hereinafter collectively referred to as “the minute object characteristic measurement device 800” as appropriate) according to the first to fifth embodiments of the fourth embodiment described above are capable of holding a plurality of minute objects. A holding member, a drive system capable of independently driving the plurality of holding members, a cantilever facing the minute object held by any of the plurality of holding members, one of the holding member for holding the minute object and the cantilever And a driving device capable of driving in the direction in which the minute object held by the holding member and the cantilever approach and separate from each other.

  In the method of measuring minute object characteristics according to the first to fifth embodiments of the fourth embodiment, a minute object is held by one holding member of a plurality of holding members that can be independently driven by a driving system, and the driving system is used. And the step of causing the minute object held by the one holding member to face the cantilever, and one of the holding member holding the minute object and the cantilever, the minute object held by the holding member Driving in a direction toward and away from the cantilever.

  According to the minute object characteristic measuring apparatus 800 and the minute object characteristic measuring method of the fourth embodiment, for example, even when the measurement of a minute object with a wide size distribution or a plurality of different measurements are continuously performed, measurement is performed from a plurality of holding members. It is possible to quickly select and use a suitable holding member for the As a result, measurement efficiency can be improved.

  On the other hand, if the minute object characteristic measuring apparatus is provided with a single holding member, it is necessary to replace the holding member with a member suitable for measurement, and the replacement takes time, so that the measurement efficiency can not be improved.

  In addition, since the minute object characteristic measuring apparatus 800 can continuously and efficiently measure the characteristics of a plurality of minute objects, for example, even in the case of continuously measuring the characteristic that easily changes with time, such as the charge amount. Accuracy can be improved.

  Further, the minute object characteristic measuring devices 800 a and c to e of Examples 1 and 3 to 5 are characteristics for each minute object by separating using a plurality of holding members even if a plurality of minute objects are aggregated. It can measure.

  In addition, the minute object characteristic measurement devices 800a, 800d, and 800e according to the first, fourth, and fifth embodiments include two holding members provided so as to face each other, so that the holding suitable for different measurement contents is performed. It is possible to smoothly carry out the operation of holding small objects between members and the separation operation of aggregated small objects.

  In addition, each of the two holding members provided opposite to each other has two arms for holding a minute object, and at least one of the two holding members is rotated about an axis parallel to the longitudinal direction. Since this is possible, it is possible to carry out the change of holding of the minute objects between the holding members and the separation of the aggregated minute objects while suppressing the interference between the holding members.

  In the minute object characteristic measuring devices 800c to 800e of the third to fifth embodiments, the plurality of holding members are two holding members provided such that axes parallel to the longitudinal direction form a right angle when viewed from the Z axis direction. Including.

  In this case, the installation space can be made smaller than providing two holding members opposite to each other, and in the case where a plurality of minute objects are aggregated, they can be separated depending on the aggregation state. The axis parallel to the longitudinal direction of the plurality of holding members when viewed from at least one direction is not limited to a right angle, and it is only necessary to form an angle.

  The minute object characteristic measurement apparatus 800b according to the second embodiment includes two holding members in which a plurality of holding members are provided such that axes parallel to the longitudinal direction are substantially parallel.

  In this case, the installation space can be made smaller than providing two holding members so as to face each other.

  Further, in the minute object characteristic measuring devices 800a to 800e according to the first to fifth embodiments, since each of the two holding members has two arms for holding the minute objects, it is possible to ensure an arbitrary minute object from above the component. Can be collected.

  In addition, since the opening widths of the two arms of the two holding members are different, the range of sizes of the small objects that can be held is broadened, and the characteristics of the various objects of various sizes can be measured without replacing the holding members. .

  Further, in the minute object characteristic measurement devices 800a to 800e of the first to fifth embodiments, since the plurality of holding members include the holding members having conductivity, the electric resistance / dielectric constant can be obtained by holding the minute objects by the holding members. It can measure.

  Further, in the minute object characteristic measuring devices 800 a to 800 e according to the first to fifth embodiments, since the plurality of holding members include the insulating holding members, the adhesion force / charge amount can be obtained by holding the minute objects by the holding members. It can measure.

  As a result, in the minute object characteristic measuring devices 800a to 800e of the first to fifth embodiments, the adhesion / charge amount measurement and the electric resistance / dielectric constant measurement can be continuously performed without replacing the holding member.

  Preferably, the plurality of holding members include a holding member having water repellency. Contamination of the holding member can be suppressed by holding the minute member that easily contaminates the holding member not having water repellency by the holding member having water repellency. In addition, since it is expensive to treat all the holding members with water repellant, only some of the holding members are treated with water repellant, and the remaining water repellant treatment is applied to the minute objects that are difficult to contaminate the holding members. It is preferable to use a non-applied holding member.

  The measuring apparatus is not limited to those described in the above-described embodiments and the modifications, and may be any other apparatus that can measure the displacement of the cantilever 20. In short, it is preferable to have a configuration in which light waves, sound waves, radio waves and the like are emitted toward the cantilever 20 and the reflected waves are received.

  In each of the embodiments and the modifications described above, the holding member included in the minute object characteristic measuring device is exemplified by one holding a minute object or one adsorbing a minute object as an example, but the present invention is not limited to this. It may be any one capable of holding minute objects (preferably, capable of holding one particle at a time).

  Further, in the above-described each embodiment and each modification, although the minute object characteristic measuring device includes the processing device 60, it may not be included. In this case, control (for example, minute movement of fine movement stage 50) performed by processing device 60 may be performed manually (manually), or a human may perform an operation performed by processing device 60. In addition, even when the minute object characteristic measurement device includes the processing device 60, the minute movement of the fine movement stage 50 may be performed manually, or a human may perform the calculation performed by the processing device 60.

  The circumstances under which the inventors of the present invention have proposed the above embodiments and modifications will be described below.

  At present, micron particles are treated in various industrial products, medicines and food products. As toners used in copiers and laser printers are becoming smaller in diameter, the smallest particle in the industry has a particle size of about 5 um. The spacer silica particles between the liquid crystal panels are also about 5 um. Pharmaceutical products and food products such as wheat flour are also commonly used in micron particles. One of the leading technologies in the rapidly expanding 3D printer market is the powder lamination method, but the powder adopted by this method is also small, and particles of 10 um or less in size are also included. ing.

  As the field of handling micro particles expands in this way, various characteristics such as adhesion, charging characteristics, electrical resistance, dielectric constant, etc. are accurately evaluated so that these particles can be handled more reliably and accurately. Means are needed. In recent years, with the development of manipulation and measurement technology for minute objects called nanotechnology, a method of evaluating the properties of these micron particles in units of one particle is being developed.

  Not limited to the industrial field as described above, human cells are several to several tens of um in size, and in order to clarify their behavior, it is desirable that measurements such as adhesion characteristics can be realized.

  There is an atomic force microscope (AFM) as a representative method to meet such needs. More specifically, the particles are fixed to the tip of a silicon micro cantilever (cantilever) via an adhesive, and the force acting on the particles is measured. For example, in Reference 1 and Reference 2, separation, contact and separation of particles and members fixed at the tip of the cantilever are continuously performed, and the amount of deflection of the cantilever at the moment of separation between the particles at the tip of the cantilever and the member surface The adhesion between the cantilever and the sample surface is measured. Reference 3 evaluates the charged state of the particles at the tip of the cantilever. More specifically, the image force generated by the charge held by the particles is determined from the amount of warpage of the cantilever by bringing the grounded metal plate into close proximity to the particles at the tip of the cantilever. Furthermore, in Reference 4, the particle at the tip of the cantilever is inserted between the electrodes to which a voltage is applied, and the amount of cantilever warpage at that time is measured to evaluate the charge amount of the particle. In addition, as a method different from the atomic force microscope, in Reference 5, the adhesion force of one particle is measured using a particle capturing needle having a spring incorporated therein. Furthermore, in Reference 6, the microelectrodes are pressed against both ends of the particles to measure the electrical resistance of the particles.

Reference 1: Japanese Patent Application Laid-Open No. 2003-330264,
Reference 2: Yukiko Mizuguchi, Kento Miyamoto: Measurement and analysis of adhesion between solid surface and particle by atomic force microscopy, Konica Minolta Technical Report, Vol. 1 (2004), pp. 19-22,
Reference 3: Hiroyuki Maruyama, Rie Tsujiyama, Hiroaki Masuda: AFM study on charging of particles by slip and non-slip contact, Proceedings of the Summer Symposium of the Institute of Powder Technology, 41 (2005) pp. 67-69
Reference 4: JW Kwek, IU Vakarelski, WK Ng, JYY Heng, and RBH
Tan: Colloids and Surfaces A: Physicocheme. Eng. 385 (2011) pp. 206-212
Reference 5: Patent 4649564 Publication Reference 6: Patent 3600674

  As described above, various methods have been proposed for measuring the characteristics of one micron-sized particle. On the other hand, as a problem common to these methods, it is difficult to simultaneously measure evaluation accuracy and efficiency for any one particle attached on a part or member. In the method using the atomic force microscope described in the references 1 to 4, the operation of fixing the particles to the cantilever is a bottleneck for improving the measurement efficiency. In general, the particles are fixed to the cantilever using an epoxy adhesive, but when applying the adhesive to the cantilever, contacting the particles to the tip of the cantilever, and curing the adhesive, the total working time is several hours It spans. Although the adhesion of any particle on a member can be measured in principle with the methods of References 1 to 4 in principle, for example, when it is attempted to measure adhesion for 10 particles, it takes several tens of hours and is not practical. . Furthermore, when trying to measure the amount of charge, there is a high possibility that the state of charge changes during fixation to the cantilever, which is also difficult to measure in principle. Also in the method of measuring the electrical resistance in Reference 6, it is necessary to prepare a dedicated manipulator in order to place particles on the electrode. It is difficult to measure the electric resistance of an arbitrary particle by the method of Reference 6 alone, and a reduction in the measurement efficiency can not be avoided when performing an evaluation in combination with a manipulator to be separately prepared. The method of reference 5 can measure the adhesion for an arbitrary particle, but the measurement accuracy is a problem. That is, although the method of reference 5 calculates the adhesive force by monitoring the frequency when two objects to be measured move apart, the mechanism of monitoring the vibration state at the time of separating while holding the particles, The measured value is susceptible to the vibration of the whole device. As in the references 1 to 4, the measurement accuracy is definitely inferior to the method using an atomic force microscope.

  In order to solve the above problems (hereinafter referred to as problem 1), the present inventors act on the cantilever in a state where the holding member capable of holding a minute object and the cantilever are in contact or in proximity to each other. By measuring the force to be measured, the minute object characteristic measuring device of the first and third embodiments and the modified examples 1 and 2 for measuring the adhesion force and the charge amount (image force) of the minute object was developed. If these minute object characteristic measuring devices are used, it is possible to realize force measurement acting on the minute objects with high accuracy after collecting and holding an arbitrary minute object. In particular, it is a feature of these minute object characteristic measuring devices that the holding function of the minute objects and the force measuring function are carried by different parts. Specifically, the holding function is carried by a microgripper, micropipette or tweezers, and the force measurement is carried by a cantilever for an atomic force microscope. As described above, by separating the function of holding the minute object and the force measurement, it is possible to realize efficient measurement with the same level of accuracy as the methods of the reference documents 1 to 4. Furthermore, by making the cantilever and the holding member bear the electrode function, it becomes possible to measure the electrical characteristics of minute objects such as the electrical resistance and the dielectric constant as in the second and third embodiments.

  Furthermore, as in the third embodiment, the configuration in which the plurality of cantilevers are held can cover a plurality of measurement items. In order for researchers and engineers to proceed with quality evaluation and further mechanism analysis, it is often not sufficient to evaluate one characteristic value. On the other hand, if a plurality of devices are introduced according to the analysis content, the device introduction cost and the maintenance cost become enormous. In addition, when trying to measure multiple characteristics for the same small object, it is necessary to move the same sample of small size between multiple measuring devices, so advanced positioning technology is required and evaluation Is likely to take longer. According to the third embodiment, it is possible to measure the adhesion, the charge amount (image force), the electric resistance, and the dielectric constant in a short time without replacing the cantilever with one device.

  As described above, the problem 1 which has been difficult in the conventional minute object characteristic measuring apparatus has been solved by the first to third embodiments and the first and third modifications and the first and second modifications. Yes) also remains. Specifically, depending on the evaluation object and purpose, all the evaluations can not be performed without replacing the holding member.

  For example, problem 2 can occur when the distribution of the size of the microscopic object is wide. In the case of a micro gripper including two arms and holding micro objects at both ends by the arms, and a holding member called nano / micro tweezers, the larger the opening width between the arms, the larger the size of the object However, because the minute movement between the arms is difficult, the object to be grasped is easily damaged, and in particular, if the object to be grasped is small, the surface shape may be maintained and the object may not be grasped. Conversely, if the opening width between the arms is small, it becomes difficult to damage the object to be grasped, but of course, an object larger than the opening width can not be grasped.

  In addition, problem 2 can also occur when performing measurement with different contents (charge amount or adhesion or electrical resistance) continuously. For example, in the case of charge amount measurement, if the surface of the holding member is insulating, the charge leak of minute objects is suppressed and it becomes easier to accurately measure, but in the case of electric resistance measurement, the holding member has an electrode function. In order to be responsible, the surface must be electrically conductive. Therefore, in the case where the charge amount measurement and the electric resistance measurement are carried out successively, it becomes necessary to replace the holding member with a suitable one for each content.

  Naturally, each measurement can be performed if it is replaced with a holding member suitable for the size of a minute object or a measurement item for each measurement, but if the holding member is replaced during evaluation, the evaluation time becomes longer, The workload of the experimenter also increases.

  Further, the problem 2 may not only increase the evaluation time but also reduce the accuracy of the evaluation, specifically, the accuracy of the charge amount / adhesion measurement. When an object is charged, its charge amount decays with time. Therefore, when measuring the amount of charge, it is important to finish the evaluation in a short time, and it is desirable to avoid replacing the holding member. Even in the case of adhesive force measurement, when the charge amount is attenuated, the electrostatic adhesive force is attenuated, and as a result, the measured value of the adhesive force also decreases.

  Moreover, also when the micro thing to be measured is aggregated, the evaluation becomes difficult. In the case of measuring the charge amount (image force), the charge amount (image force) of each minute object can not be evaluated because the charges of the adjacent minute objects all act on the cantilever. Also in the measurement of the electrical characteristics, the electric resistance and the dielectric constant of each of the minute objects constituting the aggregate can not be evaluated, as it is, in the state where the minute objects are aggregated.

  Therefore, the inventors proposed the fourth embodiment in order to achieve both measurement accuracy and measurement efficiency.

  DESCRIPTION OF SYMBOLS 10 ... Holding member, 20 ... Cantilever, 30 ... Laser displacement meter, 40 ... Fixing jig (a part of drive device), 50 ... Fine movement stage (a part of drive device), 60 ... Processing apparatus, 100, 200, 300 , 400, 500, 600, 700, 800, 800 a to 800 e...

JP, 2014-119305, A

Claims (10)

A plurality of holding members each capable of holding a minute object;
A drive system capable of independently driving the plurality of holding members;
A cantilever facing the minute object held by any of the plurality of holding members;
And a driving device capable of driving one of the holding member holding the minute object and the cantilever in a direction in which the minute object held by the holding member and the cantilever approach and away from each other ,
The plurality of holding members include two holding members provided to face each other,
Each of the two holding members has two arms for holding the minute object,
At least one is rotatably der Ru fine fragment characteristic measurement apparatus about an axis parallel to the longitudinal direction of the two holding members. Wherein the plurality of holding members, at least when viewed from one direction, minute substances according to claim 1, characterized in that it comprises two hold members parallel to the longitudinal direction axis is provided at an angle Characteristic measurement device. Wherein the plurality of holding members, minute substances characteristic measuring apparatus according to claim 1, characterized in that it comprises two hold member provided so that the longitudinal direction is substantially parallel. Said two holding members, respectively, minute substances characteristic measuring device according to claim 2 or 3, characterized in that it has two arms for holding the fine fragment. The minute object characteristic measuring apparatus according to claim 1 or 4 , wherein the two holding members have different opening widths of the two arms. The minute object characteristic measurement device according to any one of claims 1 to 5 , wherein the plurality of holding members include the holding members capable of sucking the minute objects. The minute object characteristic measurement device according to any one of claims 1 to 6 , wherein the plurality of holding members include the holding members having conductivity. The minute object characteristic measurement device according to any one of claims 1 to 7 , wherein the plurality of holding members include the holding members having an insulating property. The minute object characteristic measurement device according to any one of claims 1 to 8 , wherein the plurality of holding members include the water holding member. A method of measuring a minute object characteristic using the minute object characteristic measuring device according to any one of claims 1 to 9,
Holding a minute object on one of a plurality of holding members that can be independently driven by a drive system;
Causing the minute object held by the one holding member to face the cantilever using the drive system;
Driving one of the holding member holding the minute object and the cantilever in a direction in which the minute object held by the holding member and the cantilever approach and separate from each other Method.

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