JP2004282089A - Functional element, device employing functional element, and method for manufacturing functional element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric or pyroelectric functional element satisfying requirements of high resolution, high density and high integration, and to provide an actuator and a sensor utilizing it, and an apparatus employing them. <P>SOLUTION: A piezoelectric or pyroelectric material is shaped into a wire having a diameter of 100 μm or less thus obtaining various functional elements satisfying requirements of high resolution, high density and high integration, a sensor and actuator utilizing it, and an apparatus employing them. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a functional element using a material having piezoelectricity or pyroelectricity, a method for manufacturing the same, and devices such as various sensors and actuators using the functional element.

2. Description of the Related Art Piezoelectric bodies and pyroelectric bodies made of an organic material or an inorganic material have been conventionally used for various functional elements. Piezoelectric materials are widely applied to transducers that oscillate ultrasonic waves using the piezoelectricity (d ₃₃ ) in the thickness direction (Patent Document 1, etc.), ultrasonic diagnostic devices in the medical field, and exploration devices for industrial use. Have been. Also it has been developed, such as a microphone and a speaker using the piezoelectric elongation of the piezoelectric element (such as a d _31). In addition, the flow of a liquid flowing in a tube is controlled by vibrating a piezoelectric body in close contact with a thin tube (tube), which is applied to an ink jet printer head (Patent Document 2 etc.). ing. Further, the application field of the piezoelectric body is also applied to a fine movement device such as an optical disk head and a scanner tube of a scanning probe microscope.
On the other hand, pyroelectric bodies are mainly used as temperature sensors (Patent Document 3 and the like).
In these prior arts, each of the piezoelectric body and the pyroelectric body is processed as an element having a size of a millimeter (mm) size or more. As for the processing method, a planar element is formed into a film and then cut around the periphery, a mold is molded using a mold, and a tube-shaped element is cut into a rod and then cut around and inside. There is a way to do that.
Japanese Patent Application Laid-Open No. 2001-258098 (Claims on page 2, FIG. 1, etc.) Japanese Patent Application Laid-Open No. 09-277524 (Claims on the second page, FIG. 1, etc.) Japanese Patent Application Laid-Open No. 07-35617 (Claims on the second page, FIG. 1, etc.)

In recent years, the electronics field, mainly computers and their peripheral devices, the optoelectronics field, mainly optical communication-related devices, printers, analyzers, and other mechatronics fields widely used in precision equipment, and the integration field In new fields such as ted chemistry and in-vivo measurement, high definition, high density, and high integration are becoming indispensable conditions. As a result, the miniaturization of functional elements used in these devices Highly required.
However, the piezoelectric element and the pyroelectric element in the above-described conventional technology are elements in which the size of the piezoelectric body or the pyroelectric body is equal to or larger than the millimeter size, so that it is difficult to apply them to these new fields. is there.

The present invention has been made in view of the above-described problems, and has reduced the size of a material having piezoelectricity or pyroelectricity to a millimeter size or less, and has been applied to electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement. It is an object of the present invention to provide a functional element capable of meeting demands for higher definition, higher density, and higher integration in a new field.
It is another object of the present invention to provide a method for manufacturing the miniaturized functional element.
It is still another object of the present invention to provide various devices such as functional elements, actuators, and sensors that use miniaturized functional elements.

The functional element according to the first aspect of the present invention is characterized in that a material having piezoelectricity or pyroelectricity is formed in a wire shape.
According to a second aspect of the present invention, in the functional element according to the first aspect, the material is made of an organic material.
According to a third aspect of the present invention, in the functional element according to the first or second aspect, the diameter of the wire is 100 μm or less.
The functional element according to the fourth aspect of the present invention is made of a material having piezoelectricity or pyroelectricity, and has a mass of 10 mg or less.
An actuator according to a fifth aspect of the present invention uses the functional element according to any one of the first to fourth aspects.
According to a sixth aspect of the present invention, there is provided a piezoelectric or pyroelectric sensor using the functional element according to any one of the first to fourth aspects.
According to a seventh aspect of the present invention, the functional element according to any one of the first to fourth aspects is used as a sensor for measuring the flow velocity of liquid and / or a sensor for ultrasonic diagnosis and / or a sensor for measuring temperature. It is characterized by the following.
According to an eighth aspect of the present invention, the functional element according to any one of the first to fourth aspects is inserted into a liquid transport pipe, and is operated in the liquid transport pipe to clean the inside of the pipe. It is characterized by the following.
According to a ninth aspect of the present invention, there is provided an apparatus according to the seventh or eighth aspect, which is used for treating or measuring tissue in a human body.
The method for manufacturing a functional element according to the present invention according to claim 10, wherein a template having wire-shaped holes is filled with a material having piezoelectricity or pyroelectricity, and then the template is removed. It is characterized by producing a functional element.
According to a method of manufacturing a functional element of the present invention, a needle having a sharp tip is brought into contact with a crystal surface or a film surface, and the needle is moved in one axis direction to form a crystal or a film. It is characterized in that a wire-shaped functional element is manufactured by stretching in the axial direction.

According to the present invention, since a material having piezoelectricity or pyroelectricity can be miniaturized to a millimeter size or less, functions in new fields such as electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement are performed. It is possible to achieve higher definition, higher density, and higher integration of the conductive element, actuator, sensor, and the like.
In particular, in the actuator, the movement of the element can be made more remarkable by sufficiently reducing the size of the element. For example, in a piezoelectric tube, the ratio of the amount of piezoelectric displacement to the inner diameter is increased by reducing the inner diameter. As a result, the efficiency of transporting and discharging the liquid flowing in the tube can be improved.
In a wire-shaped element, the amount of displacement can be increased by reducing the diameter of the wire, and the performance as an actuator can be greatly improved.
Furthermore, since the weight of the element can be sufficiently reduced, the element itself can be freely controlled from outside using an external magnetic field or an external electric field.

In the functional element according to the first embodiment of the present invention, a wire-shaped functional element having a millimeter size or less can be obtained by forming a material having piezoelectricity or pyroelectricity into a wire shape. Therefore, it is possible to realize various functional elements and actuators in new fields such as electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement where high definition, high density, and high integration are required. .
According to the second embodiment of the present invention, in the functional element according to the first embodiment, by using an organic material as the material, a more flexible and high-performance fine-diameter wire can be easily manufactured. it can.
According to the third embodiment of the present invention, in the functional element according to the first or second embodiment, by setting the diameter of the wire to 100 μm or less, the driving efficiency of the expansion and contraction motion and the vibration motion is increased, and the high definition is achieved. Various functional elements and actuators can be realized in new fields such as electronics, optoelectronics, mechatronics, and in-vivo measurement where high integration, high density, and high integration are required.
The functional element according to the fourth embodiment of the present invention is made of a material having piezoelectricity or pyroelectricity, and its position can be controlled from outside by setting the mass to 10 mg or less. Therefore, it is possible to realize a micro actuator such as a flow velocity measuring device, a tube cleaning device, a human body treatment device, and a human body measurement device.
The actuator according to the fifth embodiment of the present invention requires high definition, high density, and high integration by using the functional element according to any of the first to fourth embodiments. Actuators in new fields such as electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement.
The piezoelectric or pyroelectric sensor according to the sixth embodiment of the present invention uses the functional element according to any one of the first to fourth embodiments to achieve higher definition, higher density, and higher integration. Various sensors can be realized in new fields such as electronics, optoelectronics, mechatronics, integrated chemistry, and in-vivo measurement, which require integration.
A device according to a seventh embodiment of the present invention is a device according to any one of the first to fourth embodiments, wherein the functional element according to any one of the first to fourth embodiments is a sensor for measuring the flow velocity of a liquid and / or a sensor for ultrasonic diagnosis and / or a sensor for measuring temperature. As a result, it is possible to measure the flow velocity and temperature change of the liquid in the thin tube, and also the state of solid matter mixed in the fluid and the state of deposits on the inner wall of the tube. Therefore, it is possible to know the flow rate of the blood in the blood vessel in the human body and the internal state of the blood vessel.
According to an eighth embodiment of the present invention, there is provided a device for cleaning a liquid transport pipe, wherein the functional element according to any one of the first to fourth embodiments is inserted into the liquid transport pipe and operates within the liquid transport pipe. By doing so, the inside of the tube is cleaned, so that solid matter attached to the inner wall of a thin tube such as a blood vessel in the human body can be peeled off and cleaned.
The device according to the ninth embodiment of the present invention uses the device according to the seventh or eighth embodiment for treatment or measurement of tissue in a human body, and thus can reduce the flow rate of blood in blood vessels in the human body. You can know the internal condition of the blood vessel. In addition, solid substances attached to the inner wall of a thin tube such as a blood vessel in a human body can be peeled off and cleaned.
In the method for manufacturing a functional element according to the tenth embodiment of the present invention, a template having a wire-shaped hole is filled with a material having piezoelectricity or pyroelectricity, and then the template is removed. By manufacturing a functional element, a piezoelectric or pyroelectric wire-shaped functional element can be easily manufactured. In particular, by setting the diameter of the hole to 100 μm or less, a wire-like functional element suitable as an actuator in a thin tube can be easily manufactured.
The method for producing a functional element according to the eleventh embodiment of the present invention is characterized in that a needle having a sharp tip is brought into contact with a crystal surface or a film surface, and the needle is moved in one axis direction to form a crystal or a film. By manufacturing the wire-shaped functional element by extending in the uniaxial direction, a piezoelectric or pyroelectric wire-shaped functional element can be easily manufactured.

Hereinafter, a functional device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a piezoelectric or pyroelectric tube in which a piezoelectric or pyroelectric material is wound into a tube according to an embodiment of the present invention. By winding the piezoelectric or pyroelectric thin film 1 on the XX 'axis, a piezoelectric or pyroelectric tube is formed.
FIG. 2 shows a configuration of a piezoelectric or pyroelectric coil in which a piezoelectric or pyroelectric material is formed in a coil shape. A piezoelectric element or a pyroelectric element having a coil shape can be realized by winding a strip-shaped thin film 2 having a width d having piezoelectricity or pyroelectricity on one axis YY '.
When the piezoelectric or pyroelectric element having the coil shape shown in FIG. 2 is manufactured, the turning pitch p of the coil is determined by the angle Θ between the axial direction around which the thin film 2 is wound and the longitudinal direction of the strip-shaped thin film. This relationship is shown in FIG. Generally, when the film has anisotropy in elastic modulus in the plane, the thin film is wound around the axis with the direction in which the elastic modulus becomes maximum as an axis. Therefore, the coil pitch p can be arbitrarily designed by cutting the band-shaped thin film 2 by appropriately adjusting the angle に shown in FIG. 3 after making the elastic modulus of the film anisotropic in advance.
The size of the piezoelectric or pyroelectric tube or coil is not particularly limited.If the size is on the order of millimeters, the surrounding and internal parts are cut after shaping the piezoelectric or pyroelectric material into a rod shape. Can be processed in the following manner. On the other hand, the use of piezoelectric or pyroelectric tubes or coils in new fields such as electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement requires sub-millimeter, Specifically, it is preferable to use a piezoelectric or pyroelectric tube or coil having an inner diameter of 100 μm or less.

Hereinafter, a piezoelectric or pyroelectric tube will be described as an example, but the same applies to a piezoelectric or pyroelectric coil. Now, the electrodes are provided on both sides of the thin film 1, when an electric field is applied to E ₃ between the electrodes, the piezoelectric strain S ₃ in the thickness direction is the inner surface and the outer surface of the tube is considered to be a free end (number It is represented by 1).
S ₃ = d ₃₃ × E ₃ (Equation 1)
Here d ₃₃ is the piezoelectric d constant in the thickness direction. Vinylidene fluoride is a polymeric ferroelectrics later as a piezoelectric material - the use of ethylene trifluoride copolymer (P (VDF-TrFE)) , the _{d 33} is known to be -40pC / N ing. Taking a case where the tube thickness (difference between the outer diameter and the inner diameter of the tube) is 10 μm and the electric field E ₃ is 10 MV / m as an example, the change in the inner diameter due to the thickness piezoelectricity is obtained from (Equation 1) and is 8 nm. . This change in inner diameter is only 8 × 10 ⁻⁵ % of the inner diameter for a tube having an inner diameter of 10 mm,
This is an extremely large change corresponding to 0.008% for the tube having a diameter of 8 nm and 8% for a tube having an inner diameter of 100 nm. As is known from the conventional ink jet technology, even in a tube having an inner diameter of 1 mm, a liquid flowing in the tube can be discharged as droplets by attaching a piezoelectric body to the outer wall and vibrating the tube. However, in the prior art, even if the vibration frequency of the piezoelectric body is set to a high frequency, it is difficult to reduce the diameter of the droplet following it. On the other hand, by reducing the tube diameter as described above, the rate of change in the inner diameter can be increased, so that more efficient and high-definition control of the droplet size and transport of the liquid are possible. .

  Next, a method of manufacturing a piezoelectric or pyroelectric tube having an inner diameter of 100 μm or less will be described. In order to wind the thin film 1 on one axis (corresponding to the XX ′ axis in FIG. 1), at least one of the upper surface and the lower surface of the thin film 1 is given a force to shrink or expand the other than the other. There is a need to. Any method may be used as a method for giving the driving force of this force, and there is no particular limitation. For example, a "shrinking force" can be induced by bridging only the very near surface of the film surface inside either the upper surface or the lower surface of the thin film 1 having piezoelectricity or pyroelectricity. Further, the inner diameter of the tube wound on one axis can be adjusted depending on the number of cross-linking points. That is, a tube having a smaller inner diameter can be produced as the number of crosslinking points per unit surface area increases. As a method of inducing a cross-linking reaction, for example, by irradiating one of the upper surface or the lower surface of the thin film 1 having piezoelectricity or pyroelectricity with an energy beam represented by ultraviolet rays, an electron beam, an X-ray, an ion beam, or the like. It can be carried out. However, the method of inducing the crosslinking reaction is not limited to the above. The effect of the crosslinking reaction is particularly remarkable in the organic thin film.

Various methods other than the method of inducing a cross-linking reaction can be applied as a method of applying a “force to shrink” or a “force to spread” to either the upper surface or the lower surface of the thin film 1 from the other. For example, by forming a thin film made of a different material in contact with at least one of the upper surface and the lower surface of the thin film 1 having piezoelectricity or pyroelectricity, one surface of the thin film 1 tends to spread more than the other surface. "Force" or "force to shrink". For example, O. G. FIG. Schmidt, Appl. Phys. lett. , Vol. 78, p3310, 2001. This technique is a method in which when two layers of thin films made of different crystalline materials are laminated, a shear force acts on the interface between the two layers due to the difference in lattice constant between the two, and the laminated film can be wound into a tube shape. Conventionally, the application of this method is limited to a GaAs / InAs laminated film and a Si / GeSi laminated film. The difference in the constant makes it possible to apply the effect of the contraction force or extension force acting on the interface of the laminated film. Specifically, a thin film made of a material having a larger or smaller lattice constant than the material forming the piezoelectric or pyroelectric thin film 1 is laminated on the upper or lower surface of the piezoelectric or pyroelectric thin film 1. Thereby, the laminated film can be wound uniaxially such that the film having a small lattice constant is inside. In this method, a tube formed by the difference between the two lattice constants is determined.
The driving force of the “force to shrink” applied to one surface of the thin film 1 can be further obtained by laminating a thermally crosslinkable or photocrosslinkable material.

The material of the film laminated on the thin film 1 is not limited to an organic substance. Specifically, a film obtained by combining an organic or inorganic polymer or oligomer having a large number of unsaturated bonds, a monomer in combination with a photopolymerization initiator or a thermal polymerization initiator, or a film in which a dehydration / condensation reaction is induced by heat is piezoelectrically or pyrolyzed. It is effective to form a laminate on the upper or lower surface of the thin film 1 having electrical conductivity. By heating the laminated film or irradiating the laminated film with ultraviolet rays, the crosslinking reaction of the laminated additional film proceeds, and the additional film contracts. Using this force, the thin film 1 can be wound uniaxially.
A sol-gel reactive material is particularly suitable as the inorganic material having the above characteristics. In addition, any organic material having the above characteristics can be used in the present invention as long as it has an unsaturated group such as a double bond or a triple bond in a molecule, and is not particularly limited. In this case, the magnitude of the contraction force can be controlled by the length of the chain containing the crosslinkable unsaturated bond and the number of the unsaturated bond groups.

In the case of the piezoelectric or pyroelectric tube shown in FIG. 1 and the piezoelectric or pyroelectric coil shown in FIG. 2, the axial direction around which the thin film 1 is wound generally does not matter. Accordingly, the thin film 1 having piezoelectricity or pyroelectricity and the additional film laminated thereon may be a film having an isotropic elastic modulus in the plane of the thin film.
The piezoelectric tube can be applied to a tube for transporting liquid or a tube for discharging liquid. The transport and discharge performance is particularly excellent when the inner diameter of the tube is 100 μm or less, more preferably 10 μm or less. This liquid transport tube or liquid discharge tube can be applied to the formation of a so-called integrated chemistry element. By applying the present invention to an integrated chemistry device, it becomes possible to perform a highly efficient reaction and a highly sensitive analysis using a smaller amount of liquid than a conventional device.
Further, the tube for discharging liquid of the present embodiment can be applied to a head of an ink jet printer. By applying the present invention to an ink-jet head, an ink-jet head capable of printing with higher precision and higher resolution than conventional heads and free from nozzle clogging can be realized.
When applied to a tube for transporting liquid or a tube for discharging liquid, reducing the inner diameter of the piezoelectric tube increases the ratio of the amount of piezoelectric displacement to the inner diameter. To improve the efficiency of ejection.

Next, an example in which a piezoelectric or pyroelectric material is formed in a wire shape will be described.
A piezoelectric wire or a pyroelectric wire can be realized by molding a material having piezoelectricity or pyroelectricity into a wire shape.
The pyroelectric wire can be used as a temperature sensor that can be installed in a minute gap because charge is induced on the surface by a change in temperature. As for the performance as a pyroelectric sensor, the heat capacity is reduced by reducing the wire diameter, and the response speed of the pyroelectric sensor is improved.
The piezoelectric wire can expand and contract by applying a DC electric field in the direction of spontaneous polarization. Further, by applying an AC electric field in the direction of the spontaneous polarization, it is possible to vibrate at the same frequency as the driving electric field. These expansion and contraction movements and vibration movements can be used as actuators. By reducing the wire diameter, the efficiency as the above-mentioned actuator is remarkably improved.

While miniaturization and high integration are desired in various fields, piezoelectric wires and pyroelectric wires having a small diameter of 100 μm or less are particularly useful. In the following, taking the piezoelectric wire as an example, the operation of improving the driving efficiency by reducing the wire diameter will be described.
As shown in FIG. 4, a pair of electrodes 12 and 13 facing each other is formed on a side surface of a piezoelectric wire 11 having a diameter D and a length L. Here, grounded one of the electrodes 13, an electric field is applied to E ₃ to the other electrode, the wire 11 is tube side of the side to which the electric field is applied (Fig. 4, the electrode 12 side) is extended by piezoelectricity of elongation . Relationship of the elongation strain S ₁ and the electric field E ₃ relative to the wire length (the number 2)
Is represented by
S ₁ = d ₃₁ × E ₃ (Equation 2)
When the above-mentioned vinylidene fluoride-ethylene trifluoride copolymer (P (VDF-TrFE)) is used, its d ₃₁ is 12 × 10 ⁻¹² C / N. Therefore, when the length L of the wire and the electrode is set to 10 mm, and the voltage applied between the electrodes 12 and 13 is set to 100 V, the extension length LS ₁ of the piezoelectric wire having a wire diameter D of 1 mm is 12 nm, and the extension wire LS ₁ is 12 nm. The inclination angle Θ to tan Θ = LS ₁ / D becomes 1.2 × 10 ⁻⁵ rad = 7.2 × 10 ⁻⁴ degrees. On the other hand, in a piezoelectric wire having a wire diameter D of 100 μm, the elongation length LS is 120 nm, and the inclination angle Θ to tanΘ = LS / D is 1.2 × 10 ⁻³ rad = 7.2 × 10 ⁻² degrees. The corner is improved 100 times. Further, in the case of an extremely fine piezoelectric wire having a wire diameter D of 10 μm, the elongation length LS ₁ is 1.2 μm, and the inclination angle Θ to tan Θ = LS ₁ / D is 1.2 × 10 ⁻¹ rad = 7.2 degrees. The angle of inclination is improved by a factor of 10,000 compared to a wire having a diameter of 1 mm. From the above results, it is clear that a piezoelectric wire having a wire diameter of 100 μm or less, more preferably a wire diameter of 10 μm or less has extremely high performance as an actuator.

The following method can be used as a method for producing a piezoelectric wire or a pyroelectric wire having a small diameter of 100 μm or less. That is, an organic film or an inorganic film having a cylindrical hole having an inner diameter equal to or larger than the diameter of a wire to be manufactured is used as a template, and a material having a permanent dipole is introduced into the hole to produce a piezoelectric material. Conductive wires and pyroelectric wires can be produced. FIG. 5 shows the structure of the template 15. Examples of the template 15 include a ceramic film such as porous alumina (Al ₂ O ₃ ) and a porous polycarbonate film. These porous membranes are suitable as the template 15 because they can be stably supplied with a pore diameter of several tens of μm to several tens of nm. However, the material used for the template 15 is not limited to the above-mentioned material, and may be any other film as long as it has a large number of columnar holes having a target hole diameter.

As a method for introducing a material having a permanent dipole into the holes 16 of the template 15, an electric field polymerization method can be used. Further, an evaporation method or a sputtering method in which molecules are evaporated in a vacuum and deposited in the holes 16 can be used. These methods are suitable for producing a piezoelectric wire or a pyroelectric wire using a low molecular compound such as an organic oligomer or a monomer or an inorganic material. Alternatively, a piezoelectric wire or a pyroelectric wire can be manufactured by introducing a material having a permanent dipole into the holes 16 of the template 15 in a liquid state. Specifically, it is effective to inject a material in a liquid state into a syringe or the like and inject it into the template film, or to suck the film from behind with a syringe or the like while the film is immersed in the solution (hereinafter, this method is called a solution). Injection method). This method is suitable for forming an organic polymer, oligomer, monomer material, or inorganic material by a sol-gel method.
When a material having a permanent dipole is introduced into the holes 16 in a state of being dissolved in a solvent, the volume is reduced by evaporating the solvent, and therefore, an operation of introducing a solution into the holes 16 as necessary. May be repeated several times. In that case, in order to prevent the material once solidified from being dissolved by introducing the solution into the pores again, in the case of a crystalline material, the solution is introduced into the pores 16 to evaporate the solvent. After that, it is effective to carry out heat treatment for crystallization. Crystallization makes it difficult to dissolve in the solvent when the solution is introduced again into the holes 16. Further, a metal thin film is previously formed on the surface of the holes of the template, and immersed in a solution while applying an electric field, so that a material having a permanent dipole is formed in the holes 16 by a so-called electrodeposition method or an electric field polymerization method. It is also possible to deposit them on.

The polling of the wires can be performed after the template 15 is removed, but can also be performed before the template 15 is removed. In the latter case, specifically, as shown in FIG. 5, the template 15 faces differently depending on the direction of polling for the piezoelectric wire and the pyroelectric wire (polling is performed in the longitudinal direction or the thickness direction of the wire). Polling can be performed by forming an electrode on the surface and applying a voltage.
If the template 15 is unnecessary, it can be removed by dissolving it in a solvent. For example, an alumina template can be removed by immersion in a sodium hydroxide (NaOH) aqueous solution. In the case of a polycarbonate template, it can be removed by immersion in methylene chloride as a solvent. Templates made of materials other than those described above can also be removed by dipping in a solvent suitable for each material.

The following method can also be used as a method for producing a piezoelectric wire or a pyroelectric wire having a small diameter of 100 μm or less. That is, a needle having a sharp tip is brought into contact with the crystal surface of a film made of microcrystals having a permanent dipole, the needle is moved in one axis direction, and the crystal is stretched in one axis direction, thereby forming a piezoelectric wire. And a pyroelectric wire can be manufactured. As an example of the needle having a sharp tip shape, an operating probe microscope (SPM) such as a scanning atomic force microscope (AFM) or a scanning tunnel microscope (STM) can be used.
The above method can be applied to materials other than crystalline materials. The material forming the film may be crystalline or amorphous. The periphery is cut in advance using a needle having a sharp tip to form an isolated minute area, and then the same needle is stretched in the uniaxial direction while being in contact with the minute area. A wire similar to that of a crystal can be formed. In this method, an organic material is suitable because stretching is easy, and an organic polymer material is particularly suitable.

A specific method for manufacturing a piezoelectric wire and a pyroelectric wire using the present manufacturing method will be described below. First, a thin film having a permanent dipole is formed on a conductive substrate. As a method for forming a film, a solution coating method, a vacuum evaporation method, an electrodeposition method, an electric field polymerization method, and the like described below can be used. After the film formation, in the case of a crystalline material, heat treatment is effective for crystallization. In a film in which clear microcrystals do not exist, a small area portion in the film is cut off from the surrounding film portion by cutting the periphery using a needle having a sharp tip, as described later, and isolated. Subsequently, a needle having a sharp tip is moved in one axis direction while being in contact with the isolated minute area portion or microcrystal portion, and the film of the microcrystal or minute area portion is stretched to produce a wire. In this case, in order to perform the stretching operation more efficiently, it is effective to heat the film to a temperature of room temperature or higher.
Subsequently, piezoelectricity and pyroelectricity can be imparted by polling the wire portion using a method described below. The piezoelectric wire and the pyroelectric wire manufactured by the above method can be peeled off from the substrate as needed, and an electrode can be formed on the surface.

The flow velocity of the liquid can be measured using the piezoelectric wire or the piezoelectric element having a coil shape according to the present embodiment. The wire or coil is stretched under tension by being inserted into the liquid stream. This generates a voltage due to the piezoelectricity of the elongation. Since the voltage increases as the flow velocity increases, the flow velocity can be measured using the voltage. Further, it is also possible to use a piezoelectric wire as an ultrasonic probe to ultrasonically diagnose the state of the deposit on the liquid or on the wall surface. Further, a temperature change can be measured as a pyroelectric element.
Piezoelectric wires or coils are particularly effective when it is desired to know the flow rate and temperature change of liquid in a thin tube, the state of deposits on the inner wall of the tube, and the state of solids mixed in the liquid. As one application example, the method is suitable for measuring the flow rate of blood in blood vessels in the human body, and measuring the state of solids mixed in blood and the state of adhesion of cholesterol on the inner wall of blood vessels. It is possible to know the internal state of the blood vessel by measuring the blood flow and the deposit on the inner wall of the blood vessel using the above-mentioned wire or coil.
The contents contained in the liquid tend to solidify and adhere to the inner wall of the thin tube for transporting the liquid. These solid substances adhering to the inner wall of the tube can be peeled off and cleaned using a piezoelectric actuator having a piezoelectric wire or coil shape. Specifically, a solid object attached to the inner wall of the tube can be peeled by inserting a piezoelectric coil or a piezoelectric wire into the tube and applying an AC voltage to cause piezoelectric vibration. Using this effect, it is possible to remove solid substances such as cholesterol adhered to the inner wall of a human blood vessel.

  Next, a piezoelectric element having a mass of 10 mg or less will be described in detail. Generally, the actuator is used while being fixed to a substrate or the like. If the actuator itself can move freely and its position can be controlled from the outside, its use will be greatly expanded. For example, it is very important that the actuator can move freely in a tube or a human body and its position can be controlled from the outside in a flow velocity measuring device, a tube cleaning device, a human body treatment device, or a human body measuring device described later. It is. In this case, it is very important that the mass of the actuator is small. The large mass requires an external force to overcome the gravitational force and requires a large-scale device. However, particularly in the case of a treatment device or a measurement device related to the human body, applying a large external force leads to an adverse effect or danger to the human body.

Hereinafter, the effect of reducing the weight of the actuator will be described by taking as an example a case where an extremely fine magnet is embedded in the actuator and an external magnetic field is applied to the magnet to move the actuator. As an example, a case will be described in which a ferrite magnet having a cubic shape with a side of 1 μm is embedded in an actuator, and a large magnetic columnar ferrite magnet is applied from the outside to apply a magnetic field in a direction against gravity to lift the actuator. The size of the magnetic pole of the ferrite is m, the area of the upper and lower surfaces of the fine magnet is S, the thickness is t, the radius of the external magnet is D, the thickness is L, the distance between the actuator and the external magnet is x, the magnetism of the external magnet is the moment density p, the magnetic permeability of vacuum and mu _0, the force F vertically applied to the actuator is expressed by equation (3).
F = (3mtSpD ² x) / (2μ ₀ (D ² + x ² ) ^3/2 ) (Equation 3)
Here, m is the same value as the residual magnetic flux density of 0.4 Wb / m ² of the ferrite magnet. Further, p is a value obtained by multiplying the residual magnetic flux density of the ferrite magnet by the thickness L of the magnet. As an example, when a ferrite external magnet having a radius of 1 m and a thickness of 100 mm is used, the vertical force F applied to the actuator is about 6 × 10 ⁻³ N. This corresponds to a gravity of 600 mg mass. For this force, the gravitational force of an actuator having a mass of 10 mg or less can be neglected. From the above description, an actuator having a mass of 10 mg or less can be freely moved using an external magnetic field, and its position can be controlled from the outside.

For the purpose of reducing the weight of the actuator, an organic piezoelectric material having a smaller specific gravity than an inorganic piezoelectric material is more suitable.
As the piezoelectric or pyroelectric material in this embodiment, an organic or inorganic piezoelectric or pyroelectric material can be used. Organic piezoelectric materials and pyroelectric materials include vinylidene fluoride polymers (PVDF) and oligomers, random copolymers of vinylidene fluoride and ethylene trifluoride (P (VDF-TrFE)), nylon 7, nylon 9, Nylon 11
And an odd-numbered nylon such as nylon 13, an alternating copolymer of vinylidene cyanide and vinyl acetate, and the like. Further, a ferroelectric liquid crystal represented by a cholesteric liquid crystal having a chiral C ^* can also be used. Inorganic piezoelectric materials and pyroelectric materials include disordered type piezoelectric materials, pyroelectric materials such as potassium hydrogen phosphate, Rochelle salt, glycine sulfate, sodium nitrate, thiourea, barium titanate crystals and titanium. A ceramic ferroelectric composed of zirconium oxide, lead titanate, or the like can be used. However, the material is not limited to the above, and any material can be used as long as the material has a permanent dipole and the direction of the dipole can be aligned.

  For example, the following method can be used to form the piezoelectric or pyroelectric thin film and the additional film laminated on at least one of the upper and lower surfaces thereof. When the polymer or oligomer is a solid or a highly viscous liquid at room temperature, these materials are dissolved in a solvent and thinly coated on a substrate using a coating device such as a spinner, a bar coater, or a slit die. The film can be formed by a coating film forming method in which the solvent is evaporated. In the case of a liquid such as an oligomer or a monomer at room temperature, the film can be directly formed by the above method without dissolving in a solvent. In the case of a ceramic material, wet film formation by a sol-gel method is also very suitable as a method for forming a piezoelectric thin film. Alternatively, a film can be formed by a dry film forming method in which a material is directly deposited or sputtered on a substrate. This dry film forming method is particularly suitable for forming a film of an organic low molecular material composed of an inorganic material, an oligomer or a monomer. Furthermore, it is also possible to form a film by an electrodeposition method or an electric field polymerization method by immersing in a solution while applying an electric field using a conductive substrate.

  In order to impart piezoelectricity to a thin film, it is necessary to perform a process called poling, which forms an spontaneous polarization by applying an electric field. Specifically, spontaneous polarization is formed in a desired direction by applying an electric field in the thickness direction of the thin film or in the in-plane direction of the thin film to align the permanent dipoles of the thin film with the direction of the electric field. This poling treatment may be performed before or after the thin film is wound on one axis. Further, in order to apply an electric field, a positive electrode and a negative electrode are generally required. However, the electrodes may be formed before or after winding the thin film on one axis. Further, it is also possible to form only one of the positive electrode and the negative electrode and perform polling by a corona electric field. Further, it is also possible to perform a poling process by applying an electric field after bringing a planar, wire-like, or needle-like electrode from outside into contact without forming an electrode on the thin film. Further, the above-described polling process may be performed at any stage of the process of manufacturing the device. That is, the poling treatment may be performed immediately after the film is formed on the substrate, or the poling treatment may be performed after the film is separated from the substrate and subjected to various processes.

  By the way, in the process of manufacturing the tube-shaped functional element, the coil-shaped functional element, and the functional element weighing 10 mg or less in the present embodiment, the purpose is to form the piezoelectric film, the pyroelectric film, and the additional film formed on the substrate. It is necessary to peel off these films from the substrate after cutting into the shape as described below. As a means for cutting the membrane into a desired shape, for example, it is effective to use a needle having a sharp tip shape. As an example, a scanning probe microscope (SPM) such as a scanning atomic force microscope (AFM) or a scanning tunnel microscope (STM) can be used. A sharp and hard probe is used as an SPM probe, and a film can be cut out by scanning over a contour to be cut while the probe is in contact with the film surface. SPM is suitable as a processing means of the present invention in that it can process from a nanometer (nm) scale to a several hundred micron (μm) scale. As a means for cutting out a film, a focused ion beam processing machine (FIB) capable of microfabrication on a micron scale is also suitable in addition to SPM. Further, the processing means in the present invention is not limited to the above, and various devices and processing means can be used according to the size of the element.

As a means for separating the film from the substrate after cutting the film into a desired shape, for example, the following method can be used. By immersing the cut substrate and the film attached to the upper surface thereof in a solvent that dissolves the substrate material but does not corrode the film material, the film can be separated from the substrate. In addition, the film can be peeled from the substrate even when immersed in a liquid that does not corrode both the substrate material and the film material. In this case, the liquid needs to have an affinity for at least one of the substrate material and the film material. Due to this affinity, the film can enter from a very small gap formed between the film and the substrate, and can be separated from the substrate by increasing the area where the gap exists. In this case, when the affinity between the liquid and the substrate material or the film material is insufficient, it is very effective to add a surfactant to the liquid. Further, as a more reliable peeling method, as shown in FIG. 6, an ultrathin layer (sacrificed very well in a peeling solvent) between the substrate 21 and the laminated film 23 and the piezoelectric or pyroelectric thin film 24 necessary for the element. It is very effective to form 22). As the material used for the sacrificial layer 22, it is important to select a material that is easily dissolved in a liquid that does not erode the substrate material 21 and a film necessary for the device. For example, a water-soluble material is suitable for a film material and a substrate material that are not eroded by water. In the case of a film material and a substrate material that are soluble in a nonpolar organic solvent, a material that is well soluble in a polar solvent is suitable. Conversely, in the case of a film material and a substrate material that are soluble in a polar organic solvent, a material that is well soluble in a nonpolar solvent is suitable.
(Example 1)

After spin-coating a methyl ethyl ketone solution (1 wt%) of P (VDF-TrFE) (copolymer molar ratio 75/25) on a conductive substrate having an Al thin film deposited on a glass substrate, heat-treating at 140 ° C. for 1 hour. A P (VDF-TrFE) thin film having a thickness of 100 nm is formed. The film is scanned by using a conductive AFM probe (spring constant 2 N / m) while applying a voltage of DC 10 V to perform a polling process. Then, using the same AFM probe, the probe is brought into contact with the film surface with a force of 1 μN while being heated to 120 ° C., and the film in the above region is cut by tracing the contour of a region having an area of about 20 μm × 20 μm. The film surface is crosslinked by setting it in a chamber and scanning with an electron beam. After forming the tube, an Au electrode having a width of about 6 μm and a length of about 20 μm is formed at an end portion which is in contact with the inner diameter of the tube after the tube is formed. Floating above the water surface. A P (VDF-TrFE) tube having a diameter of about 2 μm and a length of about 20 μm can be obtained by bringing a clean glass substrate into contact with the water surface horizontally and observing it under a microscope.
For piezoelectricity, an AFM device was used, and Jpn. J. Appl. Phys. , Vol. 37, p. 3884 (1999) and Thin Solid Films, vol. 353, p. 259 (1999).
The pyroelectricity can be confirmed by placing the sample on an AFM stage with a variable temperature and measuring the pyroelectric current using an AFM probe while changing the sample temperature.
The P (VDF-TrFE) tube obtained by performing film formation, poling, and electron beam irradiation by the method according to the above embodiment has piezoelectricity and pyroelectricity.
(Example 2)

A 0.5 wt% aqueous solution of polyvinyl alcohol (PVA) having a degree of suspension of 90 is spin-coated on a glass substrate to obtain a thin film having a thickness of 0.1 μm, and then an Au electrode is deposited on the PVA film. Next, a P (VDF-TrFE) (copolymerization molar ratio: 75/25) methyl ethyl ketone solution (2 wt%) was spin-coated on the substrate, and then heat-treated at 140 ° C. for 1 hour to form a P (VDF-TrF) having a thickness of 100 nm. TrFE) thin film can be obtained. Next, polling is performed by scanning an area of about 50 μm × 50 μm while applying a voltage of 10 V DC using an AFM device. Thereafter, a negative-type photopolymer film (thickness: 100 nm) is formed on the surface of the sample by spin coating, and the photopolymer film is sufficiently crosslinked by irradiation with ultraviolet rays. Further, an Au electrode having a width of about 9 μm and a length of about 20 μm is formed at the end of the above region in the same manner as in the first embodiment. Thereafter, a region having an area of about 20 μm × 20 μm was cut out using the same method as in Example 1, and the substrate was immersed in water to peel off the film from the substrate. A tube of P (VDF-TrFE) having a length of about 20 μm and having piezoelectricity and pyroelectricity can be obtained. Confirmation of these characteristics can be performed in the same manner as in the first embodiment.
(Example 3)

P (VDF-TrF) formed in the same manner as in Example 1 and heat-treated at 140 ° C. for 1 hour.
E) Anisotropy is generated in the elastic modulus by arranging the molecular chains of the thin film (thickness: 100 nm) in one direction. Specifically, a P (VDF-TrFE) thin film is heated to 135 ° C. and has an area of about 5
The surface of the area of 0 μm × 50 μm is scanned in one direction using an AFM probe (spring constant: 0.2 N / m). As a result, the molecular chains are arranged parallel to the scanning direction of the AFM, and the major axes of the crystals in the above-described region are all aligned perpendicular to the scanning direction. Since the elastic modulus of the crystal is higher in the molecular chain direction (the minor axis direction of the crystal in the film plane) than in the other directions, the above-mentioned treatment can express anisotropy in the elastic modulus. After applying an Au electrode to the surface of the above film using the same method as in Example 1, the film is cut out, irradiated with an electron beam, and peeled to obtain a piezoelectric and pyroelectric material having a length of about 3 μm and a diameter of about 1 μm. A coil-shaped element is obtained. In this example, a band-like portion having a width of about 0.5 μm and a length of about 50 μm is cut out from the region where the molecular chains are arranged, and the cut-out portion forms an angle with the major axis direction of the crystal (the direction in which the elastic modulus is minimum). Θ (see FIG. 3) is about 30 degrees. Confirmation of piezoelectricity and pyroelectricity can be performed in the same manner as in the first embodiment.
(Example 4)

A dimethylformamide solution (20 wt%) of P (VDF-TrFE) (copolymerization molar ratio 75/25) is taken in a syringe, and injected into a 60 μm-thick alumina filter having columnar holes with a diameter of 200 nm. Subsequently, the filter is heated to 100 ° C. to remove the solvent. It is preferable to repeat the above-described scan five times in order to fill the voids in the pores generated due to the removal of the solvent. Next, heat treatment is performed at 140 ° C. for 1 hour to crystallize. Even at this stage, since there are some gaps in the holes, the above-described injection operation (five injections and drying at 100 ° C. followed by heat treatment at 140 ° C.) is repeated once more. The alumina filter that has been subjected to the above treatment is cut into two pieces in the plane, an Al electrode is formed on the front and back surfaces of one piece, and a DC voltage of 4 kv is applied between the two to form an alumina filter. P (VDF-TrFE) injected into the filter is polled in the longitudinal direction of the filter hole. Next, another piece of the previously cut filter was placed in the chamber of the FIB apparatus, and a rod-shaped portion of about 60 μm × 1000 μm was cut out in the filter surface, and the rod-shaped piece was placed on the opposing filter cross-sectional portion. An electrode is formed, and a poling is performed in the short direction of the filter hole by applying a DC voltage of 4 kV between both electrodes. These two alumina filter pieces having different poling directions are separately immersed in an aqueous NaOH solution to dissolve the alumina filter. Thereafter, using a method similar to that of Example 1, a P (VDF-TrFE) wire and a P (VDF) wire having a diameter of about 200 nm and a length of about 60 μm that are poled in the diameter direction and P (VDF) that are poled in the length direction are formed on a glass substrate. -TrFE) wire can be obtained. Confirmation of piezoelectricity and pyroelectricity can be performed in the same manner as in the first embodiment.
(Example 5)

A P (VDF-TrFE) thin film having a thickness of 100 nm is obtained by spin-coating a P (VDF-TrFE) solution on a graphite substrate in the same manner as in Example 1 and then performing heat treatment crystallization. While the film is heated to 100 ° C., the probe is moved in one direction while a conductive AFM probe (spring constant: 40 N / m) is brought into contact with the surface of the crystal with a force of 3 μN. By this processing, the P (VDF-TrFE) microcrystal is elongated in the direction of movement of the probe, and a P (VDF-TrFE) wire having a length of about 1000 nm and a width of about 100 nm shown in FIG. 7 is obtained. Subsequently, a poling process is performed by scanning the wire surface while applying a DC voltage of 5 V using the above-mentioned AFM probe, and after the poling, a piezoelectric measurement is performed using an AFM device to obtain the P (VDF -TrFE) It can be confirmed that the wire has piezoelectricity. The pyroelectricity of the wire can be measured in the same manner as in Example 1.
(Example 6)

Using the method of Example 1, two types of tubes having different inner diameters, a P (VDF-TrFE) tube having an inner diameter of 100 μm and a P (VDF-TrFE) tube having an inner diameter of 0.5 mm, are produced. The size of the inner diameter was adjusted according to the amount of electron beam to be irradiated, and the length of each tube was about 100 μm. The film is cut out using a FIB apparatus.
Subsequently, an Al electrode is deposited on the outside of the tube. At this time, the electrodes are formed only at a length of 40 μm in the longitudinal center of the tube so that the electrodes inside and outside the tube do not come into contact with each other. Subsequently, these tubes are immersed in distilled water in which a small amount of dye is dissolved, and the tubes are filled with distilled water containing dye. Then, under a microscope, the above-mentioned dye-containing water droplet was brought into contact with a portion of one end of each tube where the external electrode was not formed, and a filter paper having excellent water absorption was applied to the other end of the tube at the end of the surface tube. Set up so that it contacts. In this state, when an AC voltage of 5 Vpp is applied between the electrodes formed inside and outside the tube for 3 minutes, the dye-containing water transported through the tube is absorbed on the surface of the filter paper, and when observed under a microscope, a substantially circular coloring is observed. The formed part is formed. When this area is measured and normalized by the area of the inner cross section of the tube and evaluated, it can be seen that the tube having an inner diameter of 100 μm has significantly improved transport efficiency as compared with the tube having an inner diameter of 500 μm. Therefore, it can be seen that the tube having an inner diameter of 100 μm or less in the piezoelectric tube of the present invention is particularly excellent in liquid transport and discharge performance.
(Example 7)

A P (VDF-TrFE) wire having a diameter of 500 μm and a diameter of 100 μm (all of these wires having a length of 100 μm) was manufactured using the same method as in Example 6, and one end of the wire was made conductive as shown in FIG. Fixed on the conductive substrate 25. In this case, the wires 11 are fixed, and the electrodes 11 are fixed under a microscope while taking care so that only one electrode 13 can be electrically connected to the conductive substrate 11. Next, the conductive cantilever 26 (spring constant 0.2 N / m) installed in the AFM device is fixed near the fixed end of the wire 11 and on the electrode 12 not installed on the substrate 21. When an electric field is applied between the electrodes 12 and 13 in this state, the wire 11 expands and contracts due to its piezoelectricity. A DC voltage of 100 V was applied between both electrodes 12 and 13, and the inclination of each wire due to piezoelectricity was measured. The inclination of the wire is measured by irradiating a laser beam having a small diameter near the tip of the wire and measuring the position of the reflected light.
In the above description, when the movement distance of the tip of the wire 11 (the inclination angle of the wire 11) is compared during the piezoelectric response of the wire 11, these values are remarkably improved in a wire having a diameter of 100 μm as compared with a wire having a diameter of 500 μm. Therefore, it is understood that a piezoelectric P (VDF-TrFE) wire having a diameter of 100 μm or less has high performance as an actuator.
(Example 8)

As shown in FIG. 9, a polymethacrylate (PMMA) plate 31 in which a cylindrical hole 32 having an inner diameter of 50 μm is processed is manufactured. Further, a P (VDF-TrFE) coil-shaped element having an inner diameter of 10 μm and having a piezoelectric property manufactured by using the method of Embodiment 3 and a piezoelectric P (VDF-VDF-T) having a diameter of 10 μm manufactured by using the method of Embodiment 4 were used. A TrFE) wire (each having a length of 100 μm) 34 is prepared. Next, carbon powder is vapor-deposited in the holes 32 of the polymethacrylate (PMMA) plate 31, and it is confirmed by microscopic observation that soot is uniformly attached to the holes 32. A P (VDF-TrFE) coil-shaped element 33 and a P (VDF-TrFE) wire 34 are inserted into the hole 32. After performing the above preparation, an AC voltage of 5 Vpp and 60 Hz is applied between the two electrodes provided on the coil-shaped element 33 and the wire 34 for 1 minute in the same manner as in the ninth embodiment. Observing the state of adhesion of the carbon soot under a microscope, it can be seen that soot is cleanly removed within a distance of 100 μm or less from the surface of the PMMA plate 31 in any of the samples. From this result, it is understood that the actuator according to the present invention can be applied to a cleaning apparatus for cleaning a fine pipe.
(Example 9)

A cylindrical plastic container having an inner diameter of 10 mm and a depth of 100 mm and a cylindrical plastic container having an inner diameter of 1 mm and a depth of 10 mm were placed 100 mm apart from a disk-shaped ferrite magnet having a radius of 100 mm and a thickness of 10 mm. On the other hand, a P (VDF-TrFE) wire having a radius of 3 mm and a length of 40 mm and a P (VDF-TrFE) wire having a radius of 0.3 mm and a length of 4 mm were produced, and all of them were cubic with a side of 10 μm. Each of the micro ferrite magnets having the following is embedded. These wires weighed about 2 g and 2 mg, respectively. When a P (VDF-TrFE) wire is placed in the cylindrical container having an inner diameter of 10 mm and 1 mm, the P (VDF-TrFE) wire having a radius of 0.3 mm floats in the air due to magnetic force, but a P (VDF-TrFE) having a radius of 3 mm. TrFE) wire does not float. Therefore, it can be seen that an actuator using a P (VDF-TrFE) wire having a mass of 2 mg can be easily moved by an external magnetic field. If this mass is 10 mg or less, it can be controlled by an external magnetic field.
(Example 10)

As shown in FIG. 10, a printer head 40 for an ink jet printer is manufactured using a P (VDF-TrFE) tube 41 having an inner diameter of 20 μm and having a piezoelectricity used in Example 6, and the printer head 40 is set to red and blue. Is connected to an ink tank 42 filled with an aqueous ink in which green dyes are dissolved, and the ink is injected into the printer head 40 by applying pressure by a pump. In this state, by applying a rectangular wave voltage of 5 Vpp intermittently for 30 msec between the electrodes formed on the printer head 40, the ink droplet 43 can be ejected. According to the printer head 40 having this configuration, very high-precision point drawing can be performed as compared with the conventional head.
(Example 11)

An integrated chemistry element can be manufactured using a P (VDF-TrFE) tube having an inner diameter of 50 μm and having piezoelectricity used in Example 6. FIG. 11 shows the configuration of the integrated chemistry element in this embodiment. The A terminal 51 on one end and the B terminal 52 on the other end of the element 50 are connected to a tank 53 filled with an aqueous solution of polyvinyl alcohol (Solution A) and a tank 54 filled with an aqueous solution of blue dye (Solution B), respectively. Then, the liquid in the tanks 53 and 54 is introduced into the tubes 55 and 56 using the surface tension. Next, when an AC voltage of 5 Vpp and 1 Hz is applied to the electrodes formed on the tubes 55 and 56, the inner diameters of the tubes 55 and 56 expand and contract due to the piezoelectric expansion and contraction, and the liquid A and the liquid B filled therein are filled in the area 57. The liquid A and the liquid B can be mixed in the area 57.
Note that the peak of polyvinyl alcohol and the blue dye can be confirmed by infrared spectroscopic measurement of the liquid that has been subjected to the mixing operation in the area 57. Further, a tube 58 can be further connected to the area 57 to mix three or more kinds of liquids.
(Example 12)

  A 2 nm-thick carbon film is deposited on one electrode of a poled P (VDF-TrFE) thin film having an area of 10 mm × 10 mm and having different masses (1 g and 10 mg) and is colored black, and the output power is 2 mW on the carbon film. The He-Ne laser light was irradiated while being turned ON and OFF, and the response time of the pyroelectric voltage generated between the electrodes when ON and OFF was measured. It can be seen that is significantly improved. The reason why this phenomenon occurs is that when the area is kept constant and the film thickness is reduced to reduce the weight, the heat capacity of the film is significantly reduced and the response speed is improved.

  The functional element according to the present invention is used for devices requiring high definition, high density, and high integration, such as actuators and sensors, in the fields of electronics, optoelectronics, mechatronics, integrated chemistry and in-vivo measurement. can do.

The perspective view which shows the structure of the tubular functional element in this invention. The perspective view which shows the structure of the coil-shaped functional element in this invention. FIG. 2 is a conceptual diagram illustrating a direction in which a thin film is cut out in the process of manufacturing the coil-shaped functional element in the present invention The perspective view which shows the structure of the wire-shaped functional element in this invention. The perspective view of the template used for manufacture of the wire-shaped functional element in this invention. Side view explaining another manufacturing method of a tubular functional element in the present invention. A photograph showing an AFM image of the wire-shaped functional element according to the present invention. FIG. 3 is a conceptual diagram illustrating a method of confirming expansion / contraction operation due to piezoelectricity of a wire-shaped functional element in an embodiment of the present invention. FIG. 3 is a perspective view for explaining a method of confirming an operation when the actuator according to the present invention is applied to a cleaning device in a pipe. Conceptual diagram for explaining the operation when the actuator according to the present invention is applied to an ink jet printer head Conceptual diagram for explaining the operation when the actuator according to the present invention is applied to an integrated chemistry element

Explanation of reference numerals

1, 2 Thin film 11 Wire 12, 13 Electrode 15 Template 16 Void 21 Substrate material 22 Sacrificial layer 23 Laminated film 24 Piezoelectric or pyroelectric thin film 25 Conductive substrate 26 Cantilever 31 PMMA plate 32 Hole 33 Coiled element 34 Wire 40 Printer head 41 Tube 42 Ink tank 43 Ink droplet 50 Element 51 A terminal 52 B terminal 53, 54 Tank 55, 56, 58 Tube 57 Area

Claims (11)

  A functional element, wherein a piezoelectric or pyroelectric material is formed in a wire shape.   The functional element according to claim 1, wherein the material is made of an organic material.   The functional element according to claim 1, wherein a diameter of the wire is 100 μm or less.   A functional element comprising a piezoelectric or pyroelectric material and having a mass of 10 mg or less.   An actuator using the functional element according to any one of claims 1 to 4.   A piezoelectric or pyroelectric sensor using the functional element according to claim 1.   An apparatus characterized in that the functional element according to any one of claims 1 to 4 is used as a sensor for measuring the flow velocity of liquid and / or a sensor for ultrasonic diagnosis and / or a sensor for measuring temperature.   An apparatus characterized in that the functional element according to any one of claims 1 to 4 is inserted into a liquid transport pipe, and is operated in the liquid transport pipe to clean the inside of the pipe.   An apparatus using the apparatus according to claim 7 or 8 for treating or measuring tissue in a human body.   A method for producing a functional element, comprising: filling a template having wire-shaped holes with a material having piezoelectricity or pyroelectricity; and removing the template to produce a wire-shaped functional element. A wire-shaped functional element is manufactured by bringing a needle having a sharp tip into contact with a crystal surface or a film surface and moving the needle in a uniaxial direction to extend the crystal or the film in a uniaxial direction. Of manufacturing a functional element.

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