JP2013240875A - Piezoelectric actuator, and manipulator including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piezoelectric actuator capable of obtaining high responsiveness and capable of suppressing vibration other than in an axial direction of a drive shaft.SOLUTION: A piezoelectric actuator micromotion-drives a capillary by a piezoelectric element for operating a micro object. The piezoelectric actuator includes: a pipette holding member having the capillary mounted and threaded around its circumference; a housing having an inner peripheral surface coaxial with the pipette holding member; at least two rolling bearings for supporting the pipette holding member to be rotatable with respect to the housing; the piezoelectric element disposed coaxially with the pipette holding member; a lid fixed to the housing for axially fixing the piezoelectric element; and an inner ring spacer disposed between inner rings of the two rolling bearings.

Description

  The present invention relates to a piezoelectric actuator and a manipulator that operate a minute object such as a cell.

  In the biotechnology field, a manipulator is known that operates on a minute object such as a cell such as injecting a sperm or DNA solution into an egg or cell under a microscope (see, for example, Patent Document 1). Patent Document 2 discloses a microscope apparatus that uses an electric manipulator having an operating needle to easily set the tip of an operating needle such as a glass capillary near the target position of the sample, and focuses the focus. Switch between interlocking and non-interlocking with the manipulator drive and drive the operating needle to set the operating needle.

  Patent Documents 3 to 5 describe manipulators that perforate eggs or the like by applying an impact load to the glass capillary or the like using a piezoelectric actuator including a piezoelectric element in order to enable stable micro movement of the glass capillary or the like. Has been.

JP 2004-325836 A JP 2006-23487 A Japanese Patent Publication No. 06-98582 JP 2003-1574 A JP 2008-46228 A

  In the manipulator described in Patent Document 3, the piezoelectric actuator is fixed only to a pipette holding member to which a glass capillary or the like is attached, and is not fixed to the manipulator. In such a configuration, there is a possibility that the pipette holding member is dropped when the manipulator is driven. Further, in the manipulator disclosed in Patent Document 3, the pipette holding member is fixed by a contact member that holds a small portion of the entire pipette holding member with a frictional force. There was a problem that responsiveness was affected.

  In the manipulator described in Patent Document 4, the pipette holding member and the piezoelectric actuator are not arranged coaxially, and the axis of the pipette holding member and the axis of the piezoelectric actuator are in a twisted relationship. Further, the drive shaft of the piezoelectric actuator is separated from the pipette holding member. For this reason, the glass capillary tends to vibrate other than the axial direction of the drive shaft. Furthermore, since a preload is applied to the piezoelectric element by a tension spring, it is difficult to obtain high responsiveness in terms of preload adjustment.

  In the manipulator described in Patent Document 5, a piezoelectric actuator is used in which two rolling bearings are arranged as spring elements and are coaxial with the pipette holding member. For this reason, highly accurate positioning is possible, and vibrations other than in the axial direction can be suppressed to some extent. However, in this piezoelectric actuator, a cylindrical portion for fixing the rolling bearing to an axis disposed on the central axis of the piezoelectric actuator and an abutting portion for positioning one end of the rolling bearing in the axial direction (the cylindrical portion and the outer portion). It is necessary to form a portion in which the diameter is changed and a step is formed, and a thread portion for screwing a lock nut for fixing the position of the other end in the axial direction of the rolling bearing. From such a configuration, it is difficult to configure the pipette holding member and the shaft of the piezoelectric actuator as a single member, and as a result, there is a problem that the manufacturing cost increases. Further, since the pipette holding member and the shaft of the piezoelectric element are configured separately, the dimension becomes longer in the longitudinal direction, and the possibility of vibration other than in the axial direction cannot be denied.

  In view of the above, an object of the present invention is to provide a piezoelectric actuator and a manipulator having high responsiveness, and to provide a piezoelectric actuator and a manipulator that suppress vibrations other than the axial direction of the drive shaft of the piezoelectric actuator. Moreover, it aims at providing the piezoelectric actuator and manipulator which can suppress manufacturing cost.

  In order to achieve the above object, in the piezoelectric actuator of the present embodiment, a pipette holding member equipped with a capillary, a housing having an inner peripheral surface coaxial with the pipette holding member, and the pipette holding member supported by the housing At least two rolling bearings, a piezoelectric element arranged coaxially with the pipette holding member, a lid fixed to the housing and fixing the piezoelectric element in an axial direction, and an inner ring of the two rolling bearings And a hollow member interposed between the inner ring of the two rolling bearings and the outer peripheral surface of the pipette holding member.

  According to this configuration, since the pipette holding member, which is the drive shaft, and the piezoelectric element are arranged coaxially, vibrations other than the axial direction of the drive shaft of the piezoelectric actuator can be suppressed.

  Further, it is preferable that the pipette holding member is threaded on the outer periphery, and the two rolling bearings are fixed in the axial direction by two lock nuts screwed with the outer periphery of the pipette holding member.

  It is preferable that a rotation prevention mechanism for suppressing relative rotation between the pipette holding member and the housing is provided. Thereby, relative rotation between the pipette holding member and the housing can be suppressed, and a highly accurate operation is possible.

  In the rotation preventing mechanism, it is preferable that the shape of the fitting portion between one of the lock nuts and the housing or a member interlocking with the movement of the housing is a non-cylindrical shape.

  The anti-rotation mechanism has a non-cylindrical shape as a shape of a fitting portion between one of the lock nuts and the housing or a member interlocking with the movement of the housing, and the shaft of the fitting portion. In a direction view, the maximum value of any two point distance on the line forming the outer periphery of the lock nut, and the maximum value of any two point distance on the line forming the inner periphery of the housing or a member interlocking with the movement of the housing. It is preferable that the values substantially coincide.

  Further, in the rotation preventing mechanism, it is preferable that a shape of a fitting portion between one of the lock nuts and the housing or a member interlocking with the movement of the housing is a polygonal column.

  In order to achieve the above object, the manipulator of this embodiment includes the above-described piezoelectric actuator.

  According to the piezoelectric actuator and manipulator of the present invention, high responsiveness can be obtained. In addition, vibrations other than the axial direction of the drive shaft of the piezoelectric actuator can be suppressed.

It is a figure showing roughly composition of a manipulator system concerning the present invention. It is sectional drawing of the fine movement mechanism which can be used for the manipulator system of FIG. It is sectional drawing which shows the modification of the fine movement mechanism of FIG. It is sectional drawing which shows the fixing method of a capillary. It is a block diagram which shows the control system principal part by the controller 43 of FIG. It is a figure which shows the example of a screen displayed on the display part 45 of FIG. It is a perspective view which shows the specific example of the joystick of FIG. 1, FIG. It is a figure which shows roughly the relative position (a)-(d) with respect to the bottom face 22a of the petri dish 22 during operation of the capillary 35 for injection of FIG. It is a figure which shows the change of the voltage value of the piezoelectric element 92 when the capillary 35 contacts the bottom face 22a of the petri dish 22 like FIG.8 (c). It is a figure which shows the example of 2 screens displayed on the display part of FIG. It is an axial sectional view of a piezoelectric actuator provided with a detent mechanism of the first example. It is an A direction arrow directional view of FIG. 11 which shows the principal part of the 1st example of a rotation prevention mechanism. It is a perspective view which shows the housing of FIG. FIG. 12 is a view in the direction of arrow A in FIG. 11 showing a modification of the first example of the rotation preventing mechanism. FIG. 12 is a view in the direction of arrow A in FIG. 11 showing a modification of the first example of the rotation preventing mechanism. It is an axial direction sectional view of a piezoelectric actuator provided with the rotation stopping mechanism of the 2nd example.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(manipulator)
FIG. 1 is a block diagram of a system using a manipulator according to the present invention. In FIG. 1, a manipulator system 10 includes a microscope unit 12, a manipulator 14, and a manipulator 16 as a system for performing an artificial operation on a sample that is a minute object such as a cell under microscope observation. The manipulators 14 and 16 are separately arranged on both sides of the microscope unit 12.

  The microscope unit 12 includes a camera 18 as an image sensor, a microscope 20, and a sample table, and a petri dish 22 is disposed on the sample table. The microscope 20 is arranged immediately above the petri dish 22. Note that the microscope 20 and the camera 18 have an integrated structure, and although not shown, a microscope is provided with a light source that emits light toward the petri dish 22.

  For example, a solution containing a sample (not shown) is accommodated in the petri dish 22. In this state, when the sample in the petri dish 22 is irradiated with light from the microscope 20 and the light reflected by the sample in the petri dish 22 (for example, a cell or an egg) enters the microscope 20, an optical image related to the cell or egg is After being magnified at 20, the image is taken by the camera 18, and the sample can be observed based on the image taken by the camera 18.

  As shown in FIG. 1, the manipulator 14 includes a pipette 24, an XY axis table 26, a Z axis table 28, and an XY axis table 26 as a manipulator having an X axis-Y axis-Z axis orthogonal configuration. A driving device 30 for driving and a driving device 32 for driving the Z-axis table are provided. A capillary 25 that is a capillary tip is attached to the tip of the pipette 24.

  The pipette 24 is connected to a Z-axis table 28, the Z-axis table 28 is arranged on the XY axis table 26 so as to be movable up and down, and the drive devices 30 and 32 are connected to a controller 43.

  The XY axis table 26 is configured to move along the X axis or the Y axis by driving the driving device 30, and the Z axis table 28 is moved along the Z axis (vertical) by driving the driving device 32. (Along the axial direction). The pipette 24 connected to the Z-axis table 28 moves as a moving area in the three-dimensional space according to the movement of the XY axis table 26 and the Z-axis table 28, and the cells in the petri dish 22 are moved through the capillary 25. Configured to hold.

  The manipulator 16 is a pipette (injection pipette) holding member 34, an XY axis table 36, a Z axis table 38, and a drive device 40 that drives the XY axis table 36, as a manipulator having an orthogonal three-axis configuration, A driving device 42 for driving the Z-axis table 38 is provided. The pipette holding member 34 is connected to the Z-axis table 38. The Z-axis table 38 is disposed on the XY axis table 36 so as to be movable up and down. 40 and 42 are connected to the controller 43. A glass capillary 35 is attached to the tip of the pipette holding member 34.

The XY axis table 36 is configured to move along the X axis or the Y axis by driving the driving device 40, and the Z axis table 38 is moved along the Z axis (vertical) by driving the driving device 42. (Along the axial direction). The pipette holding member 34 connected to the Z-axis table 38 moves as a moving area in the three-dimensional space according to the movement of the XY axis table 36 and the Z-axis table 38, and the sample in the petri dish 22 is passed through the capillary 35 and the like. And is configured to perform an artificial operation.
Thus, the manipulators 14 and 16 have substantially the same configuration, and the manipulator 16 to which the pipette holding member 34 is connected will be described below as an example.

  The XY axis table 36 is configured to move along the X axis or the Y axis by the drive (motor) of the drive device 40, and the Z axis table 38 is moved to the Z axis by the drive (motor) of the drive device 42. It is configured to move along the axis (along the vertical axis direction). Further, the Z-axis table 38 is connected to a pipette holding member 34 that holds a capillary 35 into which cells and eggs in the petri dish 22 are to be inserted.

  That is, the XY axis table 36 and the Z axis table 38 are moved by driving the driving devices 40 and 42 using a three-dimensional space including cells in the petri dish 22 as a moving region. The XY axis table 36 and the Z axis table 38 are, for example, a pipette holding member from the tip end side of the pipette holding member 34 to an insertion position for inserting the capillary 35 into a cell (sample) in the petri dish 22. 34 is coarsely moved. The XY axis table 36 and the Z axis table 38 are configured as such a coarse movement mechanism (three-dimensional axis movement table).

  Further, the connecting portion between the Z-axis table 38 and the pipette holding member 34 has a function as a nanopositioner. The nanopositioner supports the pipette holding member 34 so as to be freely movable in the direction in which the pipette holding member 34 is installed (longitudinal direction), and further finely drives the pipette holding member 34 along the longitudinal direction (axial direction). It is configured.

  Specifically, a connecting portion between the Z-axis table 38 and the pipette holding member 34 is provided with a fine movement mechanism 44 as a nanopositioner. Next, this fine movement mechanism will be described.

(Fine motion mechanism)
As shown in FIG. 2, the fine movement mechanism 44 includes a piezoelectric actuator 44 a including a pipette holding member 34. The piezoelectric actuator 44a includes a housing 48 that constitutes a main body of the piezoelectric actuator 44a. A pipette holding member 34 whose outer periphery is threaded is inserted into a housing 48 whose inner periphery is formed in a cylindrical shape. The pipette holding member 34 has a capillary 35 attached and fixed to the tip side (the left side in FIG. 2, the same applies hereinafter), and the rear end side (the right side in FIG. 2, the same applies to the following) for injection into eggs or cells. A tube (not shown) for feeding the solution is connected. A flow rate adjusting pump is connected to the other end of the tube.

  The pipette holding member 34 is supported by the housing 48 via rolling bearings 80 and 82. The rolling bearings 80 and 82 include inner rings 80a and 82a, outer rings 80b and 82b, and balls 80c and 82c inserted between the inner rings 80a and 82a and the outer rings 80b and 82b, respectively. And the outer rings 80b and 82b are fitted to the inner peripheral surface of the housing 48 to rotatably support the pipette holding member 34.

  The inner rings 80 a and 82 a are fitted to the pipette holding member 34 via the hollow member 84. Thereby, it is not necessary to thread the inner peripheral surfaces of the inner rings 80a and 82a, and it is possible to fit the outer peripheral surface of the pipette holding member 34 subjected to the thread processing. Further, the attachment of the rolling bearings 80 and 82 to the pipette holding member 34 is simplified.

  Further, the hollow member 84 has a flange portion 84a (inner ring spacer) protruding radially outward at a substantially central portion in the axial direction. Inner rings 80a and 82a of rolling bearings 80 and 82 are arranged on both axial sides of the flange portion 84a. Thereafter, lock nuts 86 and 86 are screwed into the pipette holding member 34 from the front end side of the inner ring 80a and the rear end side of the inner ring 82a, and the axial positions of the rolling bearings 80 and 82 are fixed. The axial dimension of the hollow member 84 is smaller than the sum of the axial dimension of the inner rings 80a and 82a of the rolling bearings 80 and 82 and the axial dimension of the flange portion 84a of the hollow member 84. For this reason, the axial front end side of the inner ring 80 a and the axial rear end side of the inner ring 82 a protrude in the axial direction from the hollow member 84. As a result, the inner rings 80a and 82a are directly fixed in the axial direction by the lock nuts 86 and 86, so that the axial movement of the inner rings 80a and 82a can be restricted.

  An annular spacer 90 that is disposed coaxially with the rolling bearings 80 and 82 and is fitted to the inner peripheral surface of the housing 48 with a positive gap is disposed on the rear end side in the axial direction of the outer ring 82b. An annular piezoelectric element 92 is disposed substantially coaxially with the spacer 90 on the rear end side in the axial direction of the spacer 90, and a housing cover 88 is disposed on the rear end side in the axial direction. The lid 88 is for fixing the piezoelectric element 92 in the axial direction, and has a hole through which the pipette holding member 34 is inserted. The lid 88 is fastened to the side surface of the housing 48 with a bolt (not shown). The lid 88 may be fixed by threading the inner peripheral surface of the housing 48 in the axial rear end side and the outer peripheral surface of the lid 88 and screwing them together. A moment may occur. For this reason, it is preferable that the lid 88 is fastened and fixed by a bolt or the like.

  The rolling bearings 80 and 82 and the piezoelectric element 92 are preloaded by adjusting the length of the spacer 90 and tightening the lid 88. Specifically, when the length of the spacer 90 is adjusted and the lid 88 is closed, the fastening force corresponding to the position is applied to the outer ring 82b of the rolling bearing 82 and the outer ring 80b of the rolling bearing 80 along the axial direction. As well as a preload is applied to the piezoelectric element 92 at the same time. As a result, a predetermined preload is applied to the rolling bearings 80 and 82 and the piezoelectric element 92, and a gap 94 is formed as a distance between the axial directions between the outer rings 80 b and 82 b of the rolling bearings 80 and 82.

  As described above, since the preload can be applied by the rolling bearings 80 and 82 which are highly rigid spring elements, the preload adjustment of the piezoelectric element 92 can be easily performed, and high responsiveness can be achieved.

  Further, since the piezoelectric element 92 is in contact with the rolling bearing 82 via the spacer 90, a piezoelectric element having a special shape such as a piezoelectric element having the same diameter as the outer ring 82b or a piezoelectric element having a dimension capable of applying a predetermined preload is used. There is no need to use it. That is, in the example of FIG. 2, the annular piezoelectric elements 92 may be arranged in a rod shape or prismatic shape so as to be substantially even in the circumferential direction of the spacer 90, and have a hole portion through which the pipette holding member 34 is inserted. A square tube may be used. Further, if the shape of the spacer 90 is made highly accurate, the inner peripheral surface of the housing 48 is formed with an accuracy that can be fitted to the rolling bearings 80 and 82. The rolling bearing 82 can be pressed evenly. In the following, “the piezoelectric element is (substantially) coaxial” does not only indicate that the center axis is shared with an axis having an annular piezoelectric element, but is centered on an axis with a piezoelectric element. This includes the case where they are arranged equally on the circumference and the case where a certain axis passes through the center of a piezoelectric element of a rectangular tube.

  The piezoelectric element 92 is connected to a controller 43 as a control circuit via a lead wire (not shown), and expands and contracts along the longitudinal direction (axial direction) of the pipette holding member 34 according to the voltage from the controller 43. It is constituted as one element of the piezoelectric actuator. That is, the piezoelectric element 92 expands and contracts along the axial direction of the pipette holding member 34 in response to the applied voltage from the controller 43, and finely moves the pipette holding member 34 along the axial direction. When the pipette holding member 34 finely moves along the axial direction, this fine movement is transmitted to the capillary 35, and the position of the capillary 35 is finely adjusted.

  As the voltage waveform of the voltage applied to the piezoelectric element 92, a sine wave, a rectangular wave, a triangular wave, or the like can be used. As a method of applying a voltage to the piezoelectric element 92, a signal waveform may be continuously output and driven while the operator is pressing the button 43B, or a burst waveform may be used.

  In the present embodiment, the displacement amount of the inner ring 80a and the outer ring 80b of the rolling bearing 80 of the rolling bearings 80 and 82, and half of the expansion / contraction amount of the piezoelectric element 92 is set as the displacement amount of the capillary 35. The piezoelectric element 92 is applied with a fine movement voltage obtained by adding a control voltage for giving a displacement twice the fine movement displacement amount and an initial setting voltage.

  For example, when 2 × elongation occurs in the piezoelectric element 92, the pressing force due to the elongation presses the outer ring 82b of the rolling bearing 82 in addition to the preload before performing fine movement control, and the outer ring 80b of the rolling bearing 80 is axially moved. , The gap 94 between the outer rings of the rolling bearings 80 and 82 is further narrowed by 2 × to absorb the axial extension of the piezoelectric element 92.

  The displacement of the gap 94 occurs when the bearings 80 and 82 are each displaced by x in the axial direction along with the elastic deformation, and the outer ring 80b of the bearing 80 is displaced by 2x in accordance with the axial direction.

  Conversely, when the piezoelectric element 92 contracts by 2x, the pressing force decreases, the elastic deformation of the rolling bearings 80 and 82 decreases by x, and the outer ring 80b of the rolling bearing 80 is aligned with the axial direction so that the gap 94 is widened. Therefore, the displacement of the piezoelectric element 92 is absorbed.

  In this way, since the rolling bearings 80 and 82 absorb the displacement x of the gap 94 separately for each x, the inner rings 80a and 80b of the rolling bearings 80 and 82 are balanced when the forces pressing the rolling bearings 80 and 82 are balanced. Is displaced together with the pipette holding member 34 in the axial direction. That is, half of the expansion / contraction amount 2x of the piezoelectric element 92 becomes the fine movement displacement amount of the capillary 35, and the capillary 35 is inserted into the insertion position. After the capillary 35 is positioned at the insertion position, when an injection voltage is applied to the piezoelectric element 92, the capillary 35 performs an injection operation.

According to the above-described configuration, since the capillary 35 and the piezoelectric element 92 are coaxially arranged, excessive vibration, that is, vibration generated in a direction other than the axial direction of the pipette holding member 34 is reduced when the piezoelectric element 92 is driven. can do.
2 is directly fixed to the manipulator 16, and the pipette holding member 34 is directly fixed to the piezoelectric actuator 44a. For this reason, the number of parts for fixing to the manipulator 16 and the pipette holding member 34 can be reduced. Improved assembly and cost reduction by reducing the number of parts. Furthermore, since the piezoelectric actuator 44a and the pipette holding member 34 are directly fixed, the distance between the piezoelectric element 92 and the capillary 35 can be shortened, and high-precision drilling by the piezoelectric element 92 can be realized.

  Next, the method of assembling such a piezoelectric actuator 44 a is as follows. First, the pipette holding member 34 in the order of the lock nut 86, the rolling bearing 80, the hollow member 84, the rolling bearing 82, and the lock nut 86 from the tip side of the pipette holding member 34. The outer peripheral surface is fitted. At this time, the rolling bearings 80 and 82 are fitted to the outer peripheral surface of the hollow member so as to sandwich the flange portion 84a therebetween. Thereafter, the relative positions of the rolling bearings 80 and 82 and the pipette holding member 34 are fixed by tightening the lock nuts 86 and 86. Then, the spacer 90 is disposed on the rear end side of the pipette holding member 34 so as to abut against the outer ring 82 b of the rolling bearing 82, and the piezoelectric element 92 is disposed so as to abut against the spacer 90. Finally, the assembly of the housing 48 is positioned so as to have the arrangement shown in FIG. 2, and the lid 88 and the housing 48 are fixed with bolts or the like. In this way, the piezoelectric actuator 44a can be easily assembled.

    FIG. 3 is a cross-sectional view showing a modification of the fine movement mechanism. In the fine movement mechanism 144 of this example, since the hollow member 135 is provided on the outer periphery of the pipette holding member 134 and the hollow member 135 is integrated with the piezoelectric actuator 144a, the pipette holding member 134 and the piezoelectric actuator 144a can be separated. Is possible. 3, parts equivalent to those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The pipette holding member 134 has a capillary 35 attached and fixed to the tip side thereof (the left side in FIG. 3, the same applies hereinafter). In addition, a nozzle for connecting a tube (not shown) for sending a solution for injection into an egg, a cell, or the like is fixed to the rear end side (the right side in FIG. 3, the same applies hereinafter) by screwing or the like. . A flow rate adjusting pump is connected to the other end of the tube. Next, the piezoelectric actuator 144a attached to the pipette holding member 134 will be described.

    Rolling bearings 80 and 82 are fitted to the outer peripheral surface of the hollow member 135 that forms the central axis of the piezoelectric actuator 144a. The inner ring 80 a of the rolling bearing 80 is positioned by contacting an abutting surface 135 b formed on the outer peripheral surface of the hollow member 135. An inner ring spacer 184 is provided between the inner rings 80 a and 82 a of the rolling bearings 80 and 82. The inner ring spacer 184 is fitted to the outer peripheral surface of the hollow member 135. The rolling bearings 80 and 82 (inner rings 80a and 82a) are fixed in the axial direction by screwing a lock nut 86 into the hollow member 135 from the rear end side of the inner ring 82a.

  Other parts of the piezoelectric actuator 144a are the same as those in FIG. That is, the housing is fitted to the outer peripheral surfaces of the outer rings 80b and 82b of the rolling bearings 80 and 82, as in FIG. The spacer 90 and the piezoelectric element 92 are disposed in this order on the inner peripheral surface of the outer ring 82b in the axial direction rear end side, and are fixed by tightening the lid 88. In this way, the piezoelectric actuator 144a integrated with the hollow member 135 is configured.

    In order to fix the pipette holding member 134 to the piezoelectric actuator 144 a, the hollow member 135 is fitted and fixed to the outer peripheral surface of the pipette holding member 134. A part of the outer peripheral surface of the pipette holding member 134 is enlarged to be provided with a stepped portion 134a. The hollow member 135 is provided with a stepped portion 135a corresponding to the stepped portion 134a on the inner diameter side, and is positioned in the axial direction by making both face each other. The hollow member 135 positioned in the axial direction is fixed to the pipette holding member 134 by a set screw (not shown). More specifically, a plurality of screw holes (not shown) penetrating in the radial direction are provided in the protruding portion 135c protruding in the axial direction from the housing 48 in the axial front end portion (left side in FIG. 3) of the hollow member 135. ing. A plurality of set screws (not shown) are screwed into the plurality of screw holes and brought into contact with the pipette holding member 134. Thereby, the pipette holding member 134 is fixed.

  By configuring the fine movement mechanism 144 as described above, the pipette holding member 134 and the piezoelectric actuator 144a can be separated. As a result, the maintainability of the fine movement mechanism 144 can be improved. Further, since the hollow member 135 is fixed with a set screw, the coaxiality and relative position between the hollow member 135 and the pipette holding member 134 can be finely adjusted. Since such a set screw is provided on the projecting portion 135c of the hollow member 135, it is easy to attach and remove the set screw, so that the maintainability of the fine movement mechanism 144 can be further improved.

  In the case of the fine movement mechanism 44 shown in FIG. 2, since it is necessary to perform a wide range of screw processing from the front end to the rear end of the pipette holding member 34, the pipette holding member 34 may be deformed. On the other hand, in the fine movement mechanism 144 of FIG. 3, it is not necessary to thread the pipette holding member 34. For this reason, deformation due to processing of the pipette holding member 134 and the hollow member 135 can be suppressed.

  In the above example, the hollow member 135 and the pipette holding member 134 are fixed by a set screw. However, the present invention is not limited to this, and adhesive fixing, press-fit fixing, and screwing fixing may be used. However, in consideration of the effects described above, fixing with a set screw is preferable. In the above example, the axial position is determined by the step, but the present invention is not limited to this, and the axial position may be determined only by the set screw without providing the step portion. It is good also as a structure which shows. Furthermore, in the above-described example, after the piezoelectric actuator 144a is assembled, the hollow member 135 and the pipette holding member 134 that form a part of the piezoelectric actuator 144a are fitted and fixed, but the present invention is not limited to this. That is, after the hollow member 135 is fitted and fixed to the pipette holding member 134, other components of the piezoelectric actuator 144a may be assembled, and the above-described effects are not based on the assembling procedure. However, when assembling property is considered, it is preferable to fix the hollow member 135 and the pipette holding member 134 after assembling the piezoelectric actuator 144a.

Other configurations and operational effects are the same as those of the fine movement mechanism of FIG.
Next, a method for fixing the capillary at the tip of the fine movement mechanism shown in FIGS.

(Capillary fixing method)
FIG. 4 is a cross-sectional view showing a method for fixing the capillary 35.
As shown in FIG. 4, an enlarged diameter portion 34 a for inserting the capillary 35 is formed at the tip of the pipette holding member 34 (134, the same applies hereinafter). The inner diameter of the enlarged diameter portion 34 a is set larger than the outer diameter of the capillary 35. On the outer periphery of the tip of the pipette holding member 34, a holding member 136 having an arrow-shaped cross section and a hollow inside on the inner diameter side is fitted. The rear end side of the capillary 35 is enclosed in the enlarged member 34 a of the holding member 136 and the pipette holding member 34.

  The inner peripheral surface of the holding member 136 includes a small diameter portion 136a on the front end side and a large diameter portion 136b on the rear end side. The small diameter portion 136 a has an inner diameter slightly larger than the outer diameter of the capillary 35. When the capillary 35 is fixed, the small diameter portion 136a guides the capillary 35 to a rough position where the capillary 35 is fixed in the radial direction. The large diameter portion 136 b has an inner diameter slightly larger than the outer peripheral surface of the pipette holding member 34. The inner peripheral surface of the large-diameter portion 136b supports the capillary 35 via two sets of support members 130. The support member 130 includes two O-rings 138 and two washers 137 that sandwich the O-ring 138. The support member 130 is disposed at two positions on the outer peripheral surface of the capillary 35 (the inner peripheral surface of the large diameter portion 136b) separated in the axial direction, and a spacer 139 is disposed therebetween. The front end side of the outer peripheral surface of the holding member 136 has a tapered shape that gradually decreases in diameter from the rear end side to the front end side. Thereby, for example, when the piezoelectric actuator 44a (144a) is operated, the petri dish 22 and the holding member are hardly brought into contact with each other. The rear end side of the outer peripheral surface of the holding member 136 is male threaded.

  A cylindrical nut member 139 is attached to the rear end side of the holding member 136 on the outer peripheral surface of the pipette holding member 34. The inner peripheral surface of the front end side of the nut member 139 is internally threaded so as to be screwed with the external thread of the holding member 136. Further, a reduced diameter portion 139a is provided on the rear end side of the nut member 139. The inner diameter of the reduced diameter portion 139 a is slightly larger than the pipette holding member 34. The pipette holding member 34 is provided with a circumferential groove, and a retaining ring 140 is fitted into the circumferential groove. The end surface on the distal end side of the reduced diameter portion 139a abuts against the retaining ring 140 and is prevented from coming off. Another example of the retaining ring 140 is a protrusion that is integral with the pipette holding member 34. In this case, the nut member 139 is inserted from the rear end side of the pipette holding member 34 before the pipette holding member is assembled to the piezoelectric actuator 44a (144a).

  The capillary 35 is supported and fixed by the holding member 136 and the nut member 139. The procedure for attaching the capillary 35 is as follows. First, the capillary 35 is inserted through the holding member 136 in which the support member 130 and the spacer 141 are assembled. In this state, the capillary is supported in the radial direction only by the O-rings constituting the two sets of support members 130. On the other hand, after attaching the nut member 139 to the pipette holding member 34, the retaining ring 140 is attached to the pipette holding member 34. Thereafter, the support member 130 on the rear end side of the holding member 136 and the tip of the pipette holding member 34 are brought into contact with each other. In this state, the nut member 139 and the holding member 136 are screwed together. Thereby, a force contracting in the radial direction acts on the threaded portion of the holding member 136, and the O-ring 138 of the support member 130 on the rear end side is deformed so as to be crushed in the radial direction. Thereby, the capillary 35 is fixed in the axial direction and the radial direction, and the support and fixing of the capillary 35 is completed. Further, the airtightness at the connecting portion between the pipette holding member 34 and the capillary 35 can be ensured by screwing the holding member 136 and the nut member 139. For this reason, the flow rate of the liquid in the capillary 35 can be adjusted with the above-described flow rate adjusting pump connected to the pipette holding member 34.

    Conventionally, a configuration in which a capillary is supported by only one support member using an O-ring is used (for example, “Eppendorf Microinjector FemtoJet (registered trademark) express usage manual”). In such a configuration, since the capillary 35 is supported only at one place, for example, when perforating the egg cell, unexpected vibration is generated in the capillary 35 by driving the piezoelectric actuator, and the cell is damaged or the efficiency is increased. May go down. On the other hand, according to the configuration shown in FIG. 4, two support members 130 each having an O-ring 138 are used and the capillary 35 is supported at two points, so that the capillary is being driven while the piezoelectric actuators 44a and 144a are being driven. It is suppressed that 35 moves. As a result, it is possible to reduce the vibration of the capillary during cell operation, and to improve the perforation performance and efficiency as compared with the conventional case.

    In the above-described configuration, two support members 130 are used. However, the present invention is not limited to this, and three or more support members 130 may be used. Further, the number of O-rings 138 constituting one support member 130 is not limited to two, but may be one or more, and the washer may be omitted. Further, the constituent members of the support member 130 are not limited to the washer 137 and the O-ring 138, and any configuration that can support the capillary can be applied.

(Manipulator control)
Next, control by the controller 43 of the manipulator system 10 will be described with reference to FIGS. FIG. 5 is a block diagram showing a main part of the control system by the controller 43 of FIG. FIG. 6 is a diagram showing an example of a screen displayed on the display unit 45 of FIG. FIG. 7 is a perspective view showing a specific example of the joystick shown in FIGS.

  The controller 43 shown in FIGS. 1 and 5 includes a CPU (Central Processing Unit) as a calculation means and hardware resources such as a hard disk, a RAM, and a ROM as storage means, and performs various calculations based on a predetermined program. The drive command is output so as to perform various controls according to the calculation result. That is, the controller 43 controls the driving devices 30 and 32 of the manipulator 14, the driving devices 40 and 42 of the manipulator 16, the piezoelectric element 92 of the fine movement mechanism 44, and the like via a driver or an amplifier provided as necessary. A drive command is output to each. For example, the piezoelectric element 92 is driven by a voltage signal generated from a signal generator 95 controlled by the controller 43 and amplified by an amplifier 96.

    The controller 43 is connected with a joystick 47, a mouse 43A, and a button 43B (FIG. 1) in addition to a keyboard as information input means, and is further connected with a display unit 45 comprising a CRT or a liquid crystal panel. In 45, a microscope image acquired by the camera 18, various control screens, and the like are displayed.

    The controller 43 automatically drives the manipulators 14 and 16 in a predetermined sequence. Such sequence driving is performed by the controller 43 sequentially outputting a drive command to each based on the calculation result of the CPU by a predetermined program.

    The display unit 45 displays a microscopic image of a minute operation target such as an egg, information on calculation results, various control buttons, and the like including images of the capillaries 25 and 35 captured by the camera 18. For example, as shown in FIG. 6, the image display unit 45 a displays a microscopic image from the camera 18. For example, an egg D that is a minute object, a capillary 25 that holds the egg D, and a capillary 35 for injection Is displayed, for example, a warning lamp 45b for setting the capillary 35 is displayed on the lower side of the image display unit 45a, and a switching button 45c for switching the magnification of the microscope image of the image display unit 45a is displayed on the upper side of the image display unit 45a. Is displayed. The switching button 45c can be operated by clicking with the mouse 43A in FIG.

    As described above, a signal voltage is applied to the piezoelectric element 92 from the amplifier 96 when the piezoelectric element 92 is driven, while the voltage generated in the piezoelectric element 92 is measured and detected by the voltage measuring unit 97 and measured. The voltage is input to the controller 43.

    Piezoelectric elements are also called piezo elements, and generally convert electrical energy into mechanical energy while converting mechanical energy into electrical energy. That is, the piezoelectric element expands and contracts when a voltage is applied, and generates a voltage when a pressure is applied.

    In this embodiment, the piezoelectric element 92 is provided in the fine movement mechanism 44 for fine movement of the capillary 35. However, when the capillary 35 comes into contact with the bottom or side surface of a container such as a petri dish, external force due to the contact is not generated. The voltage measurement unit 97 measures the voltage generated by applying to the piezoelectric element 92 via the pipette holding member 34, the rolling bearings 80 and 82, the spacer 90, etc. in FIG.

    That is, the controller 43 causes the warning lamp 45b displayed on the display unit 45 of FIG. 6 to blink in a conspicuous color such as red or yellow when the voltage measured by the voltage measurement unit 97 becomes, for example, a predetermined level or a voltage difference or more. Control to stop the drive of the capillary 35. In addition to the warning lamp 45b of the display unit 45, a warning unit 98 that blinks a lamp, generates a warning sound, or the like may be provided to activate the warning unit 98.

    For the operation of the manipulator system 10 of FIG. 1, a joystick 47 connected to the controller 43 can be mainly used as shown in FIGS. 1, 5, 7, and one manipulator 14, 16 is prepared. . The joystick 47 has a plurality of buttons 47a to 47g and a handle 47h as shown in FIG. The handle 47h is tilted (tilted) in the right direction R and the left direction L to drive the drive devices 30 and 40 in FIG. 1, and the manipulators 14 and 16 can be driven in the X axis direction and the Y axis direction to rotate (twist). Thus, the driving devices 32 and 42 can be driven to drive in the Z-axis direction. Further, the operation of each function can be assigned to each of the buttons 47a to 47g. For example, the operation of the piezoelectric element 92 of the piezoelectric actuator 44a (fine movement mechanism 44) in FIG.

    In the above configuration, when the injection manipulator 16 is driven, the handle 47h of the joystick 47 is operated to roughly drive the XY axis table 36 and the Z axis table 38, and the pipette holding member 34 is moved to the cells in the petri dish 22. After being positioned close to each other, the fine movement mechanism 44 can be used to finely drive the pipette holding member 34.

    Specifically, when the glass capillary 35 is attached to the pipette holding member 34, the manipulators 14 and 16 are driven so that the pipette holding member 34 is retracted from the petri dish 22 disposed at the microscope work site. To do. Thereby, when the capillary 35 is attached to the pipette holding member 34, a sufficient working space is obtained.

    After the capillary 35 is attached to the pipette holding member 34, the manipulator 14 is driven by a command from the controller 43 based on the operation of the joystick 47 and the like, and the pipette holding member 34 to which the capillary 35 is attached is moved to the petri dish that is a microscope work location. Move toward 22.

    When moving the capillary 35 to the microscope work location, in the first (first) operation, the switching button 45c in FIG. 6 is operated to reduce the microscope field magnification of the image displayed on the image display unit 45a, By driving the driving devices 40 and 42 and the fine movement mechanism 44 of the manipulator 16, the driving of the driving devices 40 and 42 and the fine movement mechanism 44 is stopped as soon as the capillary 35 can be confirmed in the field of view of the microscope 20.

    Thereafter, by using the image processing of the controller 43 and driving the driving devices 40 and 42 and the fine movement mechanism 44, the capillary 35 is moved to the optimum position within the field of view of the microscope 20, and the driving devices 40 and 42 and the fine movement mechanism 44 are moved. The drive of the mechanism 44 is stopped. At this time, the movement amount by the tables 36 and 38 and the fine movement mechanism 44 driven in the first operation is stored in the controller 43. In order to move the capillary to the optimum position, either or both of the XYZ driving system (XY axis table 36, Z axis table 38) and fine movement mechanism 44 by the driving devices 40 and 42 are used as appropriate.

    Next, when the manipulator 16 is operated and the petri dish or the capillary 35 needs to be replaced, the driving devices 40 and 42 and the fine movement mechanism 44 are driven, and an operation for retracting the capillary 35 from the microscope work site is performed. Do. Thereafter, the capillary 35 is driven to the set position by operating the joystick 47. In addition, you may make it retract to arbitrary positions using the button 43B.

    On the other hand, when the capillary 35 is moved again to the microscope work place, the controller 43 stores the position when it is set for the first time, so that the position of the capillary 35 can be easily adjusted by the manipulator 16. Become.

    When a capillary having a uniform shape is used as the capillary 35, the efficiency can be improved as compared with the conventional one by using the manipulator 16 according to the present embodiment. Even when the shape of the capillary 35 varies, the pipette holding member 34 can be linearly reciprocated by driving the piezoelectric actuator 44a, so that the position of the capillary 35 can be finely adjusted.

    Further, when the capillary 35 is positioned at the cell insertion position, the injection operation by the pipette holding member 34 is performed by operating the joystick 47 to apply the injection voltage to the piezoelectric element 92 and finely driving the fine movement mechanism 44. It can be performed. At this time, since the preload is applied to the piezoelectric element 92 by the rolling bearings 80 and 82 which are highly rigid spring elements, high responsiveness can be achieved.

    The operation when the capillary 35 for injection is moved to the optimum position before the injection operation and set will be further described with reference to FIGS. FIG. 8 is a diagram schematically showing relative positions (a) to (d) with respect to the bottom surface 22a of the petri dish 22 during operation of the injection capillary 35 of FIG. FIG. 9 is a diagram showing a change in the voltage value of the piezoelectric element 92 when the capillary 35 contacts the bottom surface 22a of the petri dish 22 as shown in FIG. 8C.

  As described above, when the driving devices 40 and 42 and the fine movement mechanism 44 are driven by the manipulator 16 and the capillary 35 for injection is set to the optimum position by operating the joystick 47 or the like, the capillary 35 is, for example, shown in FIG. 8), the capillary 35 approaches the bottom surface 22a of the petri dish 22 as shown in FIG. 8B, and further approaches the tip of the capillary 35 as shown in FIG. 8C. Comes into contact with the bottom surface 22a, a voltage is instantaneously generated from the piezoelectric element 92. The controller 43 (or the voltage measurement unit 97) acquires the voltage value generated from the piezoelectric element 92 and measured by the voltage measurement unit 97 in FIG. 5 at the sampling time Δt as shown in FIG. Difference ΔV (voltage difference with respect to the voltage V0 applied to the piezoelectric element 92) is calculated, and a warning is displayed if the voltage difference ΔV is equal to or greater than a predetermined value.

  For example, when the controller 43 presets the first limit value V1 of the voltage difference ΔV and the measured voltage difference ΔV becomes equal to or greater than the limit value V1 as shown in FIG. 9, for example, the display unit 45 of FIG. The warning lamp 45b flashes. By this alarm, the operator can know that the capillary 35 has contacted the bottom surface 22a of the petri dish 22. Therefore, the joystick 47 is operated and the capillary 35 is moved in the upward direction z 'as shown in FIG. 8D. And away from the bottom surface 22a. Alternatively, the driving of the manipulator 16 (the driving devices 40 and 42 and the fine movement mechanism 44) is stopped. Thereby, it is possible to prevent the capillary 35 from colliding with other parts and being broken or damaged during the position adjustment of the capillary 35.

  Further, when the controller 43 previously sets a second limit value V2 larger than the first limit value V1 and the measured voltage difference ΔV becomes equal to or greater than the second limit value V2, for example, the manipulator 16 (drive devices 40, 42). Or the fine movement mechanism 44) is automatically stopped, and the capillary 35 is forcibly stopped. Thereby, for example, when the capillary 35 is relatively strongly in contact with the bottom surface 22a and the voltage difference ΔV suddenly increases during the sampling time Δt, the further movement of the capillary 35 is stopped, so that the capillary 35 It is possible to prevent the capillary 35 from being broken or damaged during the position adjustment. In this case, the warning lamp 45b may keep blinking.

  Further, instead of flashing the warning lamp 45b in the display unit 45 described above or together with the flashing of the warning lamp 45b, another warning unit 98 is driven to flash the lamp or to emit a warning sound such as a buzzer. May be.

  Note that the voltage from the piezoelectric element 92 in the minus (−) direction as shown by the broken line in FIG. 9 depends on the contact state and timing of the other part of the capillary 35 (the capillary 25, the bottom surface 22a, the side surface 22b, etc. of the petri dish 22). When there is a possibility that a difference occurs, the absolute value of the voltage difference ΔV may be compared with the limit values V1 and V2, and another limit value is set in advance in the minus (−) direction. You may make it do.

  As a warning display on the display unit 45, for example, a warning message such as “the capillary is in contact with another part!” Is displayed in the space 45d below the screen 45a in FIG. The warning message may be displayed blinking in a conspicuous red or yellow color.

  Further, when the manipulator 16 is driven by the joystick 47 during the setting operation, the warning display is preferably on the screen of the display unit 45 of the controller 43 as described above. When the unit is built in, the vibration unit may be driven to inform the operator and warn. Further, although the manipulator 16 may be driven manually, in this case, it is preferable to drive another warning unit 98.

  Further, when measuring the voltage signal from the piezoelectric element 92, an amplifier and a filter may be installed in the voltage measuring unit 97, noise may be removed, and the voltage signal may be acquired and measured.

  As described above, according to the present embodiment, when the manipulator system 10 performs a fine operation such as injection on a cell or egg, the manipulator 16 is set when the injection capillary 35 is driven and set to a predetermined optimum position. It is possible to measure the voltage of the piezoelectric element 92 for fine movement driving provided in the controller 43, monitor the voltage value from the piezoelectric element 92 on the controller 43, detect it on the controller 43 side, and display a warning to the operator. The driving of the manipulator 16 is forcibly stopped. Thereby, it is possible to prevent the capillary 35 from coming into contact with other parts such as the capillary 25 and the bottom surface 22a and the side surface 22b of the petri dish 22 during the position adjustment of the capillary 35 and being broken or damaged.

  As described above, since the capillary 35 can be prevented from being broken, the replacement work of the capillary 35 can be made more efficient. Further, even when an operator who is not familiar with the operation at the time of setting the capillary 35 can prevent a malfunction by the operator at the time of setting the capillary by the warning display and the drive stop as described above.

(Pipette holding member detent mechanism)
In the piezoelectric actuator 44 a (144 a) used in the above-described manipulator system 10, the pipette holding member 34 (134) is supported by a rolling bearing and is not restricted in the rotational direction with respect to the housing 48. For this reason, when the pipette holding member 34 is vibrated by driving the piezoelectric actuator 44a or when external vibration is applied, the pipette holding member 34 may rotate depending on the magnitude and period of the vibration. In this case, as the pipette holding member 34 rotates, the capillary 35 fixed to the tip of the pipette holding member 34 also rotates.

  For example, as shown in FIG. 8, when a bent capillary is used as the capillary 35, when the capillary 35 rotates, the relative position between the tip of the capillary 35 and the object to be operated fluctuates, and the tip of the capillary 35 moves to the focus position of the microscope. There is a possibility that the problem of disengagement will occur. As a result, it is difficult to manipulate a minute object, which may affect the culture characteristics after the manipulation.

  In order to prevent this, when the pipette holding member 34 is used in a condition that may rotate, or when the pipette holding member 34 may affect the object to be operated, it is shown in FIGS. It is effective to use a piezoelectric actuator having a detent mechanism.

  FIGS. 11 to 13 are views showing a piezoelectric actuator 244a in which a first example of a rotation preventing mechanism is provided in the piezoelectric actuator 44a of FIG. 11 is a sectional view in the axial direction of the piezoelectric actuator 244a, FIG. 12 is a view in the direction of arrow A in FIG. 11, and FIG. 13 is a perspective view of the housing 248 of the piezoelectric actuator 244a.

  In this example, as shown in FIG. 12, of the two lock nuts attached to the piezoelectric actuator 244a, the lock nut 286 on the side fitted with the housing 248 (the tip side of the pipette holding member 34, the left side in FIG. 11). Is a hexagon when viewed from the axial direction. Further, as shown in FIG. 13, the shape of the fitting hole 248a of the housing 248 fitted with the lock nut 286 is a hexagon that fits with the outer peripheral surface of the lock nut 286 with a minute gap.

  With such a configuration, even when a rotational force is applied to the pipette holding member 34, the lock nut 286 is fixed in the rotational direction by the fitting hole 248a of the housing 248, so that the pipette holding member 34 is attached to the housing 248. It is possible to prevent relative rotation. Further, since the lock nut 286 and the fitting hole 248a are fitted with a small gap, the pipette holding member 34 is not prevented from moving relative to the housing 248 in the axial direction.

In this example, the shape of the lock nut 286 and the fitting hole 248a is hexagonal when viewed in the axial direction, but is not limited thereto. For example, the lock nut 286 and the fitting hole 248a may be polygons having substantially the same shape such as a square or an octagon, or may be oval.
Moreover, the shape of the fitting part of a lock nut and a fitting hole does not need to correspond substantially. Both of them may be other than a cylinder, and when viewed in the axial direction, the maximum value of the distance between any two points on the line forming the outer periphery of the lock nut 286 and any two points on the line forming the inner periphery of the fitting hole 248a. It is only necessary that the maximum value of the inter-distance is substantially coincident (exactly, the maximum value in the fitting hole 248a is slightly larger).

  For example, as shown in FIG. 14, a lock nut 286A having a rectangular outer peripheral shape in line contact with two opposite sides among the six sides of the hexagonal fitting hole 248a as viewed in the axial direction may be used. In this case, as compared with FIG. 12, even when the lock nut and the fitting hole are in contact with each other, the contact area is reduced, and it is difficult to prevent relative movement between the two.

  Further, as shown in FIG. 15, the fitting hole 248b has an elliptical shape when viewed in the axial direction, has a major axis substantially the same as the major axis of the fitting 248b, and is shorter than the minor axis of the fitting hole 248b. A lock nut 248 </ b> C having an elliptical outer peripheral shape having the shape may be used. In this case, even if the lock nut and the fitting hole come into contact with each other, the contact area becomes smaller than that in FIG. Although not shown, a combination of an elliptical fitting hole and a polygonal locknut, or a combination of a polygonal fitting hole and an elliptical locknut is also possible.

FIG. 16 is an axial cross-sectional view of a piezoelectric actuator 344a in which a second example of a rotation preventing mechanism is provided in the piezoelectric actuator 44a of FIG.
In this example, as shown in FIG. 16, of the two lock nuts attached to the piezoelectric actuator 344a, the lock nut 386 on the side that fits with the housing 348 (the tip side of the pipette holding member 34, the left side in FIG. 16). The outer peripheral shape of at least the tip end side of the pipette holding member is a conical tapered surface 386a whose diameter decreases toward the tip end side of the pipette holding member. And the shape of the fitting hole 348a of the housing 348 fitted with this lock nut 386 is made into the taper shape substantially equivalent to the taper surface 386a.

  In the piezoelectric actuator 344a, when the lid 88 is fixed to the housing 348, the lock nut 386 is pressed in the axial direction together with the piezoelectric element 92, the spacer 90, and the rolling bearings 82 and 80, and the taper surface 386a of the lock nut 386 is formed. It is pressed against the fitting hole 348a. As a result, the rotation of the pipette holding member 34 can be prevented by friction between the tapered surface 386a and the fitting hole 348a. In the first example of FIGS. 11 to 15, looseness (rotatable region) is generated due to a gap between the fitting hole 248 a and the lock nut 286, and the size of the looseness depends on processing accuracy. However, according to this example, the taper surface 386a and the fitting hole 348a are pressed until they come into contact with each other, so that there is no backlash.

  In this case, the pipette holding member 34 can be moved relative to the housing 348 by contracting the piezoelectric element 92. In such a configuration, when the manipulator is positioned, the piezoelectric actuator 344a is not driven, and the pipette holding member 34 is coarsely moved by the coarse movement mechanism. For example, the movement amount of the pipette holding member 34 with respect to the entire apparatus is easily rotated. This is particularly effective when

  As mentioned above, although the anti-rotation mechanism which can be used for the piezoelectric actuator which concerns on this invention was described, this structure is not limited to the form of a 1st example and a 2nd example. For example, the lock nut may be provided with a protrusion and a recess that engages with the protrusion may be provided in the housing to prevent rotation, and the lock nut may be provided with a recess and the housing may be provided with a protrusion.

  Further, the first example and the second example may be combined. That is, it is also possible to adjust the backlash in the rotational direction by expanding and contracting the piezoelectric element by making the tapered surface conical in the second example into a pyramid shape. Furthermore, it is good also as a structure provided with these and the above-mentioned recessed part and protrusion. Furthermore, it is good also as a structure which applies the outer peripheral shape of the lock nut of a 1st example and a 2nd example to a pipette holding member, and prevents rotation by fitting with a housing and a pipette holding member.

  Moreover, the shape of the lock nut arrange | positioned at the axial direction rear end side of a pipette is not specifically limited in the said 1st example and a 2nd example. However, the outer peripheral shape of the lock nut on the rear end side and the inner peripheral shape of the spacer connected to the outer ring of the rolling bearing (in conjunction with the movement of the housing) are the first example, the second example, or the other examples described above. In this way, it is possible to configure a detent mechanism. Alternatively, it is possible to configure a detent mechanism for each lock nut.

In the above embodiment, although the manipulator for injection was demonstrated, the use of this invention is not limited to this.
In other words, in order to collect the sample attached to the petri dish, it may be adapted to a manipulator for applying vibration to the capillary.
In this case, by making the distance between the capillary and the piezoelectric actuator wider than in the case of the above-described embodiment, when the vibration is applied from the piezoelectric actuator, the capillary swings with the law of inertia (the motion dullness with respect to the vibration). The sample can be peeled from the base.

  According to the present invention, the injection operation and the sample peeling operation as described above can be performed by a piezoelectric actuator having a simple configuration with a small number of parts that does not require a linear motion device such as a ball screw or a motor. In addition, since the outer periphery of the pipette holding member is threaded and each part is attached with a corresponding female screw, it is easier to attach compared to the case where each part is attached by press fitting, and the capillary (pipette holding member tip Side) and the piezoelectric actuator can be easily finely adjusted.

10 Manipulator system, 14 Manipulator for holding, 16
Manipulator for injection, 18 camera, 20 microscope, 22 petri dish, 22a bottom surface, 22b side surface, 25 holding capillary, 35 injection capillary, 30, 32
Drive device, 40, 42 drive device, 43 controller, 44 fine movement mechanism, 45 display unit (monitoring means), 45a image display unit, 45b warning lamp, 45e, 45f image display unit, 47
Joystick, 92 piezoelectric element, 97 voltage measurement unit (voltage detection means), 98 warning unit (monitoring means)

Claims (7)

In a piezoelectric actuator that finely drives a capillary for manipulating a minute object with a piezoelectric element,
A pipette holding member equipped with the capillary;
A housing having an inner peripheral surface coaxial with the pipette holding member;
At least two rolling bearings for supporting the pipette holding member with respect to the housing;
A piezoelectric element disposed coaxially with the pipette holding member;
A lid fixed to the housing and fixing the piezoelectric element in the axial direction;
An inner ring spacer disposed between the inner rings of the two rolling bearings;
A hollow member interposed between an inner ring of the two rolling bearings and an outer peripheral surface of the pipette holding member;
A piezoelectric actuator comprising: The pipette holding member is threaded on the outer periphery,
2. The piezoelectric actuator according to claim 1, wherein the two rolling bearings are fixed in an axial direction by two lock nuts that are screwed to an outer periphery of the pipette holding member. The piezoelectric actuator according to claim 1, further comprising a rotation prevention mechanism that suppresses relative rotation between the pipette holding member and the housing. 4. The piezoelectric actuator according to claim 1, wherein the rotation prevention mechanism includes one of the lock nuts and a member that interlocks with the movement of the housing or the housing. 5. The anti-rotation mechanism has a non-cylindrical shape as a fitting portion between one of the lock nuts and the housing or a member interlocking with the movement of the housing,
And in the axial direction view of the fitting portion,
The maximum value of the distance between any two points on the line that forms the outer periphery of the lock nut and the maximum value of the distance between any two points on the line that forms the inner periphery of the housing or a member that interlocks with the movement of the housing are approximately The piezoelectric actuator according to claim 1, wherein the piezoelectric actuator is configured by matching. The anti-rotation mechanism is configured by forming a fitting portion between one of the lock nuts and the housing or a member interlocking with the movement of the housing into a polygonal column shape. The piezoelectric actuator according to any one of 1 to 4. A manipulator comprising the piezoelectric actuator according to claim 1.