JP2016213275A - Cloth-like transducer and device including the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cloth-like transducer having excellent flexibility, a device using the signal from the transducer, and/or a device that functions by inputting the electric signal.SOLUTION: The transducer includes piezoelectric units disposed roughly on the same plane so that conductive fibers B and a piezoelectric fiber A are electrically connected and electrostatic capacity units made of a plurality of mutually separated conductive fibers B. The piezoelectric units have contact points where the conductive fibers B and the piezoelectric fiber A are mutually physically in contact with each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transducer that outputs an electric signal and / or changes its shape by inputting an electric signal by changing its shape due to an external force. More specifically, the present invention relates to a fabric-like transducer characterized by being able to change shape flexibly and three-dimensionally.

  In recent years, so-called wearable sensors have attracted attention, and products such as glasses and watches have begun to appear in the world. However, these devices have a feeling that they are worn, and a cloth-like shape, that is, a clothing-like shape that is the ultimate wearable is desired. As such a sensor, a sensor in which a piezoelectric element is attached to a cloth and a signal is extracted therefrom is disclosed (Patent Documents 1 and 2). However, since these require a separate structure on the surface of the woven or knitted fabric, it is difficult to adapt to a free-form surface, the touch is poor, and there is a lack of practicality such as problems in handling, workability, and workability. . In addition, there is a film-like structure made of a piezoelectric material and a conductive material (Patent Document 3), but this is also difficult to adapt to a free-form surface, has poor tactile feel, and is easy to handle. , Lack of practicality, such as causing problems in workability and workability. In addition, a sensor (Patent Document 4) that detects resistance between conductive fibers is proposed as a cloth-like sensor composed of only fibers, but it detects pressure and displacement on the cloth and is directly connected to bending and twisting. It did not detect any shape change. Further, Patent Document 5 discloses a piezoelectric element that includes two conductive fibers and one piezoelectric fiber, which include piezoelectric units arranged on substantially the same plane while having contact with each other. ing. However, there has been a demand for a fabric-like piezoelectric element that can stably obtain a high-strength piezoelectric signal practically.

Special table 2007-518886 JP-A-6-323929 JP 2002-203996 A JP 2006-284276 A International Publication No. 2014/058077

  An object of the present invention is to provide a fabric-like transducer that is rich in flexibility by using a fiber material and producing a conventional knitted or knitted structure. Furthermore, it is to provide a device that uses a signal from the transducer and / or a device that functions by inputting an electric signal.

  The present inventors have discovered that they function as piezoelectric elements by combining and arranging conductive fibers and piezoelectric fibers, and have completed the present invention.

That is, the present invention includes the following inventions.
1. A transducer comprising a piezoelectric unit in which conductive fibers and piezoelectric fibers are arranged in substantially the same plane so as to provide an electrical connection, and a capacitance unit composed of a plurality of conductive fibers spaced apart from each other.
2. 2. The transducer according to claim 1, wherein in the piezoelectric unit, the conductive fiber and the piezoelectric fiber have a contact point that physically contacts each other.
3. 2. The transducer according to claim 1, wherein insulating fibers are arranged so that the conductive fibers in the piezoelectric unit are not electrically connected to conductive fibers and / or piezoelectric fibers in other piezoelectric units. .
4). 2. The transducer according to 1 above, wherein the piezoelectric fiber mainly contains polylactic acid.
5. 2. The transducer according to 1 above, wherein the piezoelectric fiber mainly contains poly-L-lactic acid or poly-D-lactic acid having an optical purity of 99% or more.
6). The transducer according to 1 above, wherein the piezoelectric fiber is uniaxially oriented and includes crystals.
7). 2. The transducer according to 1 above, wherein the conductive fiber is a metal-plated fiber.
8). 2. The transducer according to 1 above, which is a woven or knitted fabric containing a plurality of the piezoelectric units and / or a plurality of the capacitance units.
9. 9. The transducer according to 8 above, wherein the woven fabric contains a plurality of the piezoelectric units and / or a plurality of the capacitance units, and the woven structure is any of a plain weave, a twill weave, a satin weave, and a composite structure thereof. .
10. 10. The transducer according to 9 above, wherein a plurality of the woven and knitted fabrics are used in combination.
11. The transducer according to any one of 1 to 10 above, an amplification unit that amplifies an electrical signal output from the transducer in accordance with an applied pressure, and an electrical signal that is amplified by the amplification unit And an output means.
12 12. The device according to 11 above, further comprising a transmission unit that transmits the electrical signal output from the output unit to an external device.
13. A device comprising: the transducer according to any one of 1 to 10 above; and a transmission unit that transmits an electrical signal output from the transducer to an external device in accordance with an applied stress.
14 A device comprising: receiving means for receiving an electric signal; and the transducer according to any one of the above 1 to 10, to which the electric signal received by the receiving means is applied.

  According to the present invention, a fabric-like transducer having high flexibility can be obtained by using a fiber material and producing a conventional woven or knitted structure. Since the transducer according to the present invention is flexible, it is possible to realize a transducer that can input and output electric signals of any shape that can be realized by a foldable cloth shape such as a handkerchief, or a cloth shape. Furthermore, a device that uses a signal from the transducer and / or a device that functions by inputting an electric signal can be realized.

It is a schematic diagram of the circuit using the textile fabric of an Example. It is a block diagram which shows the 1st specific example of the device using the transducer of this invention. It is a block diagram which shows the 2nd specific example of the device using the transducer of this invention. It is a block diagram which shows the 3rd specific example of the device using the transducer of this invention.

  An object of the present invention is to provide a piezoelectric unit in which conductive fibers and piezoelectric fibers are arranged on substantially the same plane so as to provide electrical connection, and a capacitance unit composed of a plurality of conductive fibers spaced apart from each other. This is achieved by a transducer that outputs an electrical signal comprising: Each configuration will be described below.

(Conductive fiber)
Any known conductive fibers may be used as long as they exhibit electrical conductivity. For example, metal fibers, conductive polymer fibers, carbon fibers, fibrous or granular conductive fillers are dispersed. Examples thereof include fibers made of a polymer made to be polymerized, or fibers in which a conductive layer is provided on the surface of a fibrous material. Examples of the method for providing a conductive layer on the surface of the fibrous material include a metal coat, a conductive polymer coat, and winding of conductive fibers. Among these, a metal coat is preferable from the viewpoint of conductivity, durability, flexibility and the like. Specific methods for coating the metal include vapor deposition, sputtering, electrolytic plating, and electroless plating, but plating is preferable from the viewpoint of productivity. Such a metal-plated fiber can be referred to as a metal-plated fiber.

  As a base fiber coated with a metal, a known fiber can be used regardless of conductivity, for example, polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aramid fiber, In addition to synthetic fibers such as polysulfone fibers, polyether fibers and polyurethane fibers, natural fibers such as cotton, hemp and silk, semi-synthetic fibers such as acetate, and regenerated fibers such as rayon and cupra can be used. The base fibers are not limited to these, and known fibers can be arbitrarily used, and these fibers may be used in combination.

  Any metal may be used as long as the metal coated on the base fiber exhibits conductivity and exhibits the effects of the present invention. For example, gold, silver, platinum, copper, nickel, tin, zinc, palladium, indium tin oxide, copper sulfide, and a mixture or alloy thereof can be used.

  As the conductive fiber, a multifilament in which a plurality of filaments are bundled or a monofilament composed of a single filament may be used. The use as a multifilament is preferable from the viewpoint of long stability of electrical characteristics. When used as a monofilament, the yarn diameter is 1 μm to 5000 μm, preferably 50 μm to 1000 μm. When used as a multifilament, the single yarn diameter is 0.1 μm to 5000 μm, preferably 2 μm to 100 μm. More preferably, it is 3 micrometers-50 micrometers. The number of filaments of the multifilament is preferably 1 to 100,000, more preferably 5 to 500, and still more preferably 10 to 100.

  If the diameter is small, the strength is lowered and handling becomes difficult, and if the diameter is large, flexibility is sacrificed. The cross-sectional shape of the conductive fiber is preferably a circle or an ellipse from the viewpoint of the design and manufacture of the piezoelectric element, but is not limited thereto.

Moreover, in order to efficiently extract the electrical output from the piezoelectric polymer, the electrical resistance is preferably low, and the volume resistivity is preferably 10 ⁻¹ Ω · cm or less, more preferably 10 ⁻² Ω · cm. cm or less, more preferably 10 ⁻³ Ω · cm or less. However, the resistivity of the conductive fiber is not limited as long as strength is obtained for signal detection.

(Piezoelectric fiber)
The piezoelectric fiber is a fiber having piezoelectricity. The piezoelectric fiber is preferably made of a piezoelectric polymer. As the piezoelectric polymer, any polymer exhibiting piezoelectricity such as polyvinylidene fluoride and polylactic acid can be used, but it is preferable that polylactic acid is mainly contained. Polylactic acid is easily oriented by stretching after melt spinning and exhibits piezoelectricity, and is excellent in productivity in that it does not require an electric field alignment treatment required for polyvinylidene fluoride and the like. Furthermore, the piezoelectric fiber made of polylactic acid has a small polarization due to its tensile or compressive stress in the axial direction, and it is difficult to function as a piezoelectric element, but a relatively large electrical output can be obtained depending on the shear stress, This is preferable in the piezoelectric element of the present invention having a structure that can easily apply a shear stress to the piezoelectric polymer.

  The piezoelectric polymer preferably contains mainly polylactic acid. “Mainly” means preferably 90 mol% or more, more preferably 95 mol% or more, and still more preferably 98 mol% or more.

  As polylactic acid, depending on its crystal structure, poly-L-lactic acid obtained by polymerizing L-lactic acid and L-lactide, D-lactic acid, poly-D-lactic acid obtained by polymerizing D-lactide, and those There are stereocomplex polylactic acid having a hybrid structure, and any of them can be used as long as it exhibits piezoelectricity. From the viewpoint of high piezoelectricity, poly-L-lactic acid and poly-D-lactic acid are preferable. Since poly-L-lactic acid and poly-D-lactic acid are reversed in polarization with respect to the same stress, they can be used in combination according to the purpose.

  The optical purity of polylactic acid is preferably 99% or more, more preferably 99.3% or more, and further preferably 99.5% or more. When the optical purity is less than 99%, the piezoelectricity may be remarkably lowered, and it may be difficult to obtain a sufficient electric output due to the shape change of the piezoelectric fiber. The piezoelectric polymer mainly contains poly-L-lactic acid or poly-D-lactic acid, and the optical purity thereof is preferably 99% or more.

  The piezoelectric fiber is preferably uniaxially oriented in the fiber axis direction of the fiber and contains crystals, more preferably uniaxially oriented polylactic acid having crystals. This is because polylactic acid exhibits large piezoelectricity in its crystalline state and uniaxial orientation.

  Since polylactic acid is a polyester that hydrolyzes relatively quickly, a known hydrolysis inhibitor such as an isocyanate compound, an oxazoline compound, an epoxy compound, or a carbodiimide compound may be added when heat and moisture resistance is a problem. . Further, if necessary, the physical properties may be improved by adding an antioxidant such as a phosphoric acid compound, a plasticizer, a photodegradation inhibitor, and the like.

  Polylactic acid may be used as an alloy with other polymers, but if polylactic acid is used as the main piezoelectric polymer, it contains at least 50% by weight or more based on the total weight of the alloy. It is preferably 70% by weight or more, and most preferably 90% by weight or more.

  Examples of the polymer other than polylactic acid in the case of alloy include polybutylene terephthalate, polyethylene terephthalate, polyethylene naphthalate copolymer, polymethacrylate, and the like, but the invention is not limited thereto. Any polymer may be used as long as the desired piezoelectricity is exhibited.

  As the piezoelectric fiber, a multifilament in which a plurality of filaments are bundled or a monofilament composed of a single filament may be used. The use as a multifilament is preferable from the viewpoint of long stability of electrical characteristics. When used as a monofilament, the yarn diameter is 1 μm to 5000 μm, preferably 50 μm to 1000 μm. When used as a multifilament, the single yarn diameter is 0.1 μm to 5000 μm, preferably 2 μm to 100 μm. More preferably, it is 3 micrometers-50 micrometers. The number of filaments of the multifilament is preferably 1 to 100,000, more preferably 5 to 500, and still more preferably 10 to 100.

  In order to make the above-mentioned piezoelectric polymer into a piezoelectric fiber, any known method for fiberizing the polymer can be adopted as long as the effect of the present invention is achieved, and the piezoelectric polymer is extruded. Molding and fiberizing technique, Piezoelectric polymer melt spinning and fiberizing technique, Piezoelectric polymer fiberizing process by dry or wet spinning, Piezoelectric polymer fiberizing process by electrostatic spinning Etc. can be adopted. As these spinning conditions, a known method may be applied according to the piezoelectric polymer to be employed, and a melt spinning method that is industrially easy to produce is usually employed.

  As described above, when the piezoelectric polymer is polylactic acid, the fiber is preferably stretched because it is uniaxially stretched and exhibits greater piezoelectricity when it contains crystals.

(Almost on the same plane)
In the piezoelectric element of the present invention, the conductive fiber and the piezoelectric fiber are arranged on substantially the same plane. Here, “substantially on the same plane” means that the fiber axes of the fibers are arranged on a substantially plane, and “substantially” means that a thickness is generated at the intersection of the fibers. is there.

  For example, a form in which one piezoelectric fiber is further arranged in parallel between two parallel conductive fibers is a form on substantially the same plane. Further, even if the fiber axis of the one piezoelectric fiber is tilted in a state that is not parallel to the two parallel conductive fibers, they are substantially on the same plane. Furthermore, it is assumed that one conductive fiber and one piezoelectric fiber are aligned in parallel, and the other conductive fiber is crossed with the aligned conductive fiber and piezoelectric fiber. Are also on the same plane.

  By being arranged on a substantially flat surface, it is easy to form a cloth-like piezoelectric element by combining the piezoelectric units, and using a cloth-like piezoelectric element increases the degree of freedom in designing the shape of the transducer. Can do. Examples of the type of fabric include woven fabric, knitted fabric, and non-woven fabric.

  The relationship between the piezoelectric fiber and the conductive fiber is appropriately selected depending on the shape change to be detected.

(Arrangement order)
The arrangement of the fibers in the piezoelectric unit is not particularly limited as long as the conductive fibers and the piezoelectric fibers are arranged to provide an electrical connection. For example, when the piezoelectric unit is composed of two conductive fibers and one piezoelectric fiber, it is preferable that the conductive fibers, the piezoelectric fibers, and the conductive fibers are arranged in this order. By arranging in this way, the two conductive fibers of the piezoelectric unit do not come into contact with each other, and the piezoelectric material can be obtained without applying other means such as a technique such as coating an insulating material. It can function effectively as a unit.

  At this time, it is desirable that the conductive fiber and the piezoelectric fiber have a contact point that physically contacts each other. However, if the distance between the conductive fiber and the piezoelectric fiber is within 4 mm, An electrical connection can be provided without contact. The distance between the conductive fiber and the piezoelectric fiber is more preferably 3 mm or less, further preferably 2 mm or less, further preferably 1 mm or less, and most preferably 0.5 mm or less. If this distance exceeds 4 mm, the electrical output accompanying the shape change of the piezoelectric fiber becomes small, making it difficult to use as a transducer.

  As a form, for example, two conductive fibers are arranged in parallel, and one piezoelectric fiber is further arranged in parallel between the two conductive fibers, or two conductive fibers. Are arranged in parallel, and one piezoelectric fiber may be arranged so as to cross these two conductive fibers. Further, two conductive fibers may be arranged as warps (or wefts), and one piezoelectric fiber may be arranged as wefts (or warps). In this case, it is preferable that the two conductive fibers are not in contact with each other, and preferably, an insulating substance, for example, an insulating fiber is interposed between the two conductive fibers. It is also possible to adopt a form in which an insulating material is coated only on the surface that is easily contacted so that the conductive fiber is in direct contact with the piezoelectric fiber.

(Insulating fiber)
The piezoelectric unit of the present invention includes an insulating fiber, and the insulating fiber includes a conductive fiber and a piezoelectric fiber so that the conductive fiber in the piezoelectric unit is not in contact with other conductive fibers and the piezoelectric fiber. May be placed between. In this case, the insulating fiber may be a stretchable material or a fiber having a shape for the purpose of improving the flexibility of the fabric. In addition, the conductive fiber in the piezoelectric unit may be arranged not to contact the conductive fiber and the piezoelectric fiber in the other piezoelectric unit.

  By disposing the insulating fibers in the piezoelectric units in this way, even when a plurality of piezoelectric units are combined, the conductive fibers do not come into contact, and the performance as a transducer can be improved.

As such an insulating fiber, it can be used if the volume resistivity is 10 ⁶ Ω · cm or more, more preferably 10 ⁸ Ω · cm or more, and further preferably 10 ¹⁰ Ω · cm or more.

  Insulating fiber such as polyester fiber, nylon fiber, acrylic fiber, polyethylene fiber, polypropylene fiber, vinyl chloride fiber, aramid fiber, polysulfone fiber, polyether fiber, polyurethane fiber, cotton, hemp, silk, etc. Natural fibers, semi-synthetic fibers such as acetate, and regenerated fibers such as rayon and cupra can be used. It is not limited to these, A well-known insulating fiber can be used arbitrarily. Furthermore, these insulating fibers may be used in combination, or may be combined with a fiber having no insulating property to form a fiber having insulating properties as a whole.

  The insulating fiber may be a multifilament in which a plurality of filaments are bundled, or may be a monofilament composed of a single filament. The use as a multifilament is preferable from the viewpoint of long stability of the insulating characteristics. When used as a monofilament, the yarn diameter is 1 μm to 5000 μm, preferably 50 μm to 1000 μm. When used as a multifilament, the single yarn diameter is 0.1 μm to 5000 μm, preferably 2 μm to 100 μm. More preferably, it is 3 micrometers-50 micrometers. The number of filaments of the multifilament is preferably 1 to 100,000, more preferably 5 to 500, and still more preferably 10 to 100.

  In addition, for the purpose of imparting flexibility to the fabric, any known shape of fiber can be used.

(Piezoelectric unit combination form)
In the present invention, a woven or knitted fabric containing a plurality of parallel piezoelectric units is preferable. With such a configuration, it is possible to improve the degree of deformation (flexibility) of the shape as a piezoelectric element.

  Such a woven or knitted fabric shape includes a plurality of piezoelectric units, and there is no limitation as long as it functions as a piezoelectric element. In order to obtain a woven or knitted shape, knitting and weaving may be performed with a normal loom or knitting machine. In the case of introducing a plurality of piezoelectric units into one piece of fabric, it may be produced continuously during weaving or knitting, or may be produced by joining a plurality of separately produced fabrics.

  Examples of the woven structure of the woven fabric include a three-layer structure such as plain weave, twill weave, and satin weave, a change structure, a single double structure such as a vertical double weave and a horizontal double weave, and a vertical velvet.

  The type of knitted fabric may be a circular knitted fabric (weft knitted fabric) or a warp knitted fabric. Preferable examples of the structure of the circular knitted fabric (weft knitted fabric) include flat knitting, rubber knitting, double-sided knitting, pearl knitting, tuck knitting, floating knitting, single-sided knitting, lace knitting, and bristle knitting. Examples of the warp knitting structure include single denby knitting, single atlas knitting, double cord knitting, half tricot knitting, back hair knitting, jacquard knitting, and the like. The number of layers may be a single layer or a multilayer of two or more layers. Further, it may be a napped woven fabric or a napped knitted fabric composed of a napped portion made of a cut pile and / or a loop pile and a ground tissue portion.

  When the piezoelectric unit is incorporated in a woven or knitted structure, the piezoelectric fiber itself has a bent portion. However, in order to efficiently exhibit the piezoelectric performance as a piezoelectric element, the bending of the piezoelectric fiber is necessary. Smaller portions are preferred. Therefore, the woven fabric is preferred for the woven fabric and the knitted fabric.

  Even in this case, as described above, the piezoelectric fiber is more efficiently expressed when the bending portion of the piezoelectric fiber is smaller. Therefore, the twill weave is preferable to the plain weave as the weave structure, and the satin weave (salmon weave) than the twill weave. Is preferred. In particular, among satin woven (red satin weave), when the number of jumps is in the range of 3 to 7, it is preferable because the retention of the woven structure and the piezoelectric performance are exhibited at a high level.

  The woven structure is appropriately selected depending on the shape change to be detected. For example, when it is desired to detect bending, it is preferable that the plain weave structure and the piezoelectric fiber and the conductive fiber have a parallel relationship. When torsion detection is desired, the satin weave structure, the piezoelectric fiber and the conductive fiber are A direct relationship is preferred.

In addition, since polylactic acid, which is a piezoelectric fiber, is easily charged, it may easily malfunction. In such a case, the piezoelectric fiber from which a signal is to be taken out can be grounded (grounded). As a method of grounding (grounding), it is preferable to dispose conductive fibers separately from the conductive fibers from which signals are extracted. In this case, the volume resistivity of the conductive fiber is preferably 10 ⁻¹ Ω · cm or less, more preferably 10 ⁻² Ω · cm or less, and still more preferably 10 ⁻³ Ω · cm or less.

(Multiple piezoelectric elements)
It is also possible to use a plurality of piezoelectric elements side by side. The arrangement may be one-dimensionally arranged in one step, two-dimensionally stacked, and may be knitted into a cloth or used as a braid. Thereby, a cloth-like or string-like piezoelectric element can be realized. In forming a cloth or string, as long as the object of the present invention is achieved, the fibers may be combined with other fibers other than the piezoelectric element and mixed, woven, knitted, etc., or incorporated into a resin or the like. You may use it.

(Capacitance unit)
The transducer of the present invention includes a capacitance unit in addition to the piezoelectric unit. The capacitance unit here means that two conductive fibers are arranged so as to be spaced apart from each other in parallel and a voltage is applied between the conductive fibers, and the distance between the conductive fibers changes. The pressure and displacement applied to the fabric are detected by measuring the resistance value and the amount of electricity generated by the change in capacitance. As a method of separating two conductive fibers in parallel with each other, for example, a method of interposing an insulating fiber between two conductive fibers, or a method of sandwiching a dielectric between two conductive fibers And a method of providing a space between two conductive fibers by weaving or knitting. For detection, a signal from one capacitance unit may be used, or signals from a plurality of capacitance units connected in series and / or in parallel may be used.

  While the signal from the piezoelectric unit is generated only at the moment of displacement, the signal from the capacitance unit is always obtained during the displacement, and the signal from the capacitance unit is relatively large. There is. On the other hand, the capacitance unit is easily affected by static electricity, and may cause malfunction when used as a sensor, for example.

  Therefore, a more detailed motion analysis can be performed by using a fabric structure having both a piezoelectric unit and a capacitance unit and analyzing signals from both. For example, the specific movement of the fabric from the piezoelectric unit, that is, the type of movement such as bending and twisting and the amount of displacement thereof are detected, while the capacitance unit detects whether or not the displacement continues. It is possible to analyze the movement. Alternatively, when measuring the displacement amount of the fabric with the signal from the capacitance unit, by taking out only the signal when the signal from the piezoelectric element is detected at the same time from the obtained signals, It can be used such as to suppress malfunctions. At this time, since signals from both the piezoelectric unit and the capacitance unit are used for analysis for one movement of the fabric, the piezoelectric unit and the static unit are made to have the same movement for one movement of the fabric. The capacitance units are preferably arranged close to each other.

(Applied technology for piezoelectric elements)
Regardless of the mode of the transducer of the present invention, contact with the surface, pressure, and shape change can be output as an electrical signal. FIG. 1 is a block diagram showing a first specific example of a device using the transducer of the present invention. For example, the transducer 11 of the present invention, an amplifying unit 12 for amplifying an electric signal output from the transducer 11 in accordance with an applied pressure, and an output unit 13 for outputting the electric signal amplified by the amplifying unit 12 If the device 101 including the transmission unit 14 for transmitting the electrical signal output from the output unit 13 to an external device (not shown) is configured, the device 101 is output by contact with the surface of the transducer 11, pressure, or shape change. Since the electrical signal can be easily taken out, it can be applied to various applications. Whether the transmission method by the transmission means 14 is wireless or wired may be appropriately determined according to the device to be applied.

  Further, not only the amplification means but also known signal processing means such as noise removing means and means for processing in combination with other signals can be used in combination. The order of connection of these means can be appropriately changed according to the purpose. Of course, the electrical signal output from the transducer 11 may be signal-processed after being transmitted to the external device as it is.

  Specific examples include touchscreens, human and animal surface pressure sensors, joint and bends, torsion, and expansion / contraction in the form of clothing, supporters, handkerchiefs, including hats, gloves, and socks. Sensor. For example, when used for humans, it can be used as an interface for detecting contact and movement, collecting information on movement of joints and the like for medical purposes, amusement purposes, and moving lost tissues and robots. In addition, it can be used as a stuffed animal that imitates animals and humanoids, a surface pressure sensor of a robot, a sensor that detects bending, twisting, and expansion / contraction of a joint. In addition, it can be used as a surface pressure sensor or shape change sensor for bedding such as sheets and pillows, shoe soles, gloves, chairs, rugs, bags, and flags.

  Furthermore, since the sensor of the present invention is in the form of a cloth, it has stretchability and flexibility, so that it can be used as a surface pressure sensor or a shape change sensor by pasting or covering all or part of the surface of any structure. be able to.

  In addition, since the transducer of the present invention can take out an electrical signal as an output, it can also be used as a power generation element such as a power source for storing other devices or storing electricity. FIG. 2 is a block diagram showing a second specific example of a device using the transducer of the present invention. For example, the transducer 11 of the present invention, an amplifying unit 12 for amplifying an electric signal output from the transducer 11 in accordance with an applied pressure, and an output unit 13 for outputting the electric signal amplified by the amplifying unit 12 If the device 102 consisting of the above is configured, the electrical signal output by the contact with the surface of the transducer 11, the pressure, and the shape change is used as a power source for moving other devices, or is stored in the power storage device. Can do.

  Further, not only the amplification means but also known signal processing means such as noise removing means and means for processing in combination with other signals can be used in combination. The order of connection of these means can be appropriately changed according to the purpose. Of course, the electrical signal output from the transducer 11 may be signal-processed after being transmitted to the external device as it is.

  Specifically, power generation by using it as a moving part of a human, animal, robot, machine, etc. that moves spontaneously, power generation on the surface of a shoe sole, rug, or structure that receives pressure from the outside, shape change in fluid Power generation, etc. In order to generate an electric signal due to a shape change in the fluid, it is possible to adsorb the chargeable substance in the fluid or to suppress the adhesion.

  On the other hand, the transducer according to the present invention can generate a mechanical force when an electric signal is inputted, regardless of the mode. FIG. 3 is a block diagram showing a third specific example of a device using the transducer of the present invention. For example, if a device 103 comprising a receiving means 15 for receiving an electric signal from an external device (not shown) and the transducer 11 of the present invention to which the electric signal received by the receiving means 15 is applied, the device 103 is inputted. A force corresponding to the electrical signal can be generated in the transducer 11.

  Further, not only the amplification means but also known signal processing means such as noise removing means and means for processing in combination with other signals can be used in combination. The order of connection of these means can be appropriately changed according to the purpose. Of course, the electrical signal output from the transducer 11 may be signal-processed after being transmitted to the external device as it is.

  Specific examples of applications that use electrical signals as input include applying electrical signals to cloth-shaped piezoelectric elements to move objects placed on the fabric surface, wrapping objects, and compressing them. Or can be vibrated. Various shapes can be expressed by controlling electric signals applied to the piezoelectric elements constituting the fabric. Furthermore, it is possible to function as a speaker by vibrating the fabric itself.

  Other examples include clothing that includes hats, gloves and socks, supporters, handkerchiefs, actuators that apply pressure to the surface of people, animals and objects, bending, twisting, and stretching of joints. It is an actuator to support. For example, when used in humans, it can be used for amusement applications that give contact, movement, or pressure, or to move lost tissue. In addition, it can be used as a stuffed animal that imitates animals or humanoids, an actuator that inflates or stretches the surface of a robot, or an actuator that imparts movements such as bending, twisting, and expansion / contraction to joints. Others include actuators that move the surface of bedclothes such as sheets and pillows, shoe soles, gloves, chairs, rugs, bags, and flags, and actuators of all shapes like cloth, such as handkerchiefs, furoshikis, and bags that change shape with electrical signals. Can be used as

  Furthermore, since the actuator of the present invention is in the form of a cloth, it has stretchability and flexibility, so that it can be used as an actuator that changes the surface shape by pasting or covering all or part of the surface of any structure. .

  Since the transducer of the present invention can move with an electric signal as an input, it can also be used as a speaker that generates sound by vibration.

  Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to these examples.

Each physical property was measured by the following methods.
(1) Optical purity of polylactic acid:
Collect 0.1 g of polylactic acid fiber (one bundle in the case of multifilament) constituting the fabric, add 1.0 mL of 5 mol / liter sodium hydroxide aqueous solution / 1.0 mL of methanol, and bring to 65 ° C. Set in a set water bath shaker, hydrolyze for about 30 minutes until the polylactic acid becomes a homogeneous solution, and further add 0.25 mol / liter sulfuric acid to the hydrolyzed solution to neutralize it. 0.1 mL of the decomposition solution was collected, diluted with 3 mL of high-performance liquid chromatography (HPLC) mobile phase solution, and filtered through a membrane filter (0.45 μm). This adjustment solution was subjected to HPLC measurement, and the ratio of L-lactic acid monomer to D-lactic acid monomer was quantified. When the amount of one polylactic acid fiber is less than 0.1 g, the amount of other solution used is adjusted according to the amount that can be collected, and the concentration of polylactic acid in the sample solution used for HPLC measurement is 100 minutes from the above. It was made to be in the range of 1.
<HPLC measurement conditions>
Column: “Sumichiral (registered trademark)” OA-5000 (4.6 mmφ × 150 mm) manufactured by Sumika Chemical Analysis Co., Ltd.
Mobile phase: 1.0 mmol / liter copper sulfate aqueous solution Mobile phase flow rate: 1.0 ml / min Detector: UV detector (wavelength 254 nm)
Injection amount: 100 microliters When the peak area derived from the L-lactic acid monomer is S _LLA and the peak area derived from the D-lactic acid monomer is S _DLA , S _LLA and S _DLA are the molar concentrations M _LLA and L-lactic acid monomer. Since it was proportional to the molar concentration M _DLA of the D-lactic acid monomer, the larger value of S _LLA and S _DLA was taken as S _MLA , and the optical purity was calculated by the following formula (1).
[Equation 1]
Optical purity (%) = S _MLA / (S _LLA + S _DLA ) × 100 (1)

The fabric for the transducer was manufactured by the following method.
(Manufacture of polylactic acid)
The polylactic acid used in the examples was produced by the following method.
To 100 parts by weight of L-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%), 0.005 part by weight of octylate is added, and 180 ° C. in a reactor equipped with a stirring blade in a nitrogen atmosphere. Then, 1.2 times equivalent of phosphoric acid was added to tin octylate, and then the remaining lactide was removed under reduced pressure at 13.3 Pa to obtain chips to obtain poly-L-lactic acid (PLLA1). . The resulting PLLA1 had a weight average molecular weight of 152,000, a glass transition point (Tg) of 55 ° C., and a melting point of 175 ° C.

(Piezoelectric fiber)
PLLA1 melted at 240 ° C. was discharged from a 24-hole cap at 20 g / min and taken up at 887 m / min. This unstretched multifilament yarn was stretched 2.3 times at 80 ° C. and heat-set at 100 ° C. to obtain a 84 dTex / 24 filament multifilament uniaxially stretched yarn, which was designated as piezoelectric fiber A.

(Conductive fiber)
The silver-plated nylon product name “AGposs” made by Mitsuji Fuji Textile Industry was used. The volume resistivity of this fiber was 1.1 × 10 ⁻³ Ω · cm. This fiber was designated as conductive fiber B.

(Insulating fiber)
Polyethylene terephthalate melted at 280 ° C. was discharged from a 24-hole cap at 45 g / min and taken up at 800 m / min. This undrawn yarn was drawn at 80 ° C. and 2.5 times, and heat-fixed at 180 ° C. to obtain a multifilament drawn yarn of 84 dTex / 24 filament.

(Weaving)
As shown in FIG. 1, an insulating fiber C is arranged on the warp, a piezoelectric unit P in which the piezoelectric fiber A and the conductive fiber B are alternately arranged on the weft, an insulating fiber C is arranged on the warp, and the weft is conductive. And a capacitance unit E in which one insulating fiber C is arranged between two conductive fibers B and two conductive fibers B were produced.

The performance evaluation of the fabric was performed by the following method.
A pair of conductive fibers B in the piezoelectric unit P of the fabric were connected as signal lines to an oscilloscope 1 (digital oscilloscope DL6000 series product name “DL6000” manufactured by Yokogawa Electric Corporation) via evaluation wires 2 and 3. . Further, a pair of conductive fibers B in the capacitance unit E of the fabric was connected as signal lines to the oscilloscope 4 (same as above) via the evaluation wirings 5 and 6, and a voltage of 1V was applied. In this state, when the fabric was bent 90 degrees along a straight line QQ ′ in a direction perpendicular to the piezoelectric fiber A, a potential difference of 3.2 mV was detected by the oscilloscope 1, and an electric quantity of 5 pC was detected by the oscilloscope 4. While holding the folded state, the oscilloscope 4 continued to detect an electric quantity of 5 pC. From the above results, it was confirmed that two different signals can be detected from the piezoelectric unit P and the capacitance unit E by one displacement of the fabric.

DESCRIPTION OF SYMBOLS A Piezoelectric fiber B Conductive fiber C Insulating fiber 1 Oscilloscope 2 Evaluation wiring 3 Evaluation wiring 4 Oscilloscope 5 Evaluation wiring 6 Evaluation wiring 11 Transducer 11a Fabric 12 Amplifying means 13 Output means 14 Transmitting means 15 Receiving means 101 , 102, 103 devices

Claims (14)

  A transducer comprising a piezoelectric unit in which conductive fibers and piezoelectric fibers are arranged in substantially the same plane so as to provide an electrical connection, and a capacitance unit composed of a plurality of conductive fibers spaced apart from each other.   The transducer according to claim 1, wherein in the piezoelectric unit, the conductive fiber and the piezoelectric fiber have a contact point that physically contacts each other.   The transformer according to claim 1, wherein insulating fibers are arranged so that the conductive fibers in the piezoelectric unit are not electrically connected to conductive fibers and / or piezoelectric fibers in other piezoelectric units. Deucer.   The transducer according to claim 1, wherein the piezoelectric fiber mainly contains polylactic acid.   The transducer according to claim 1, wherein the piezoelectric fiber mainly contains poly-L-lactic acid or poly-D-lactic acid having an optical purity of 99% or more.   The transducer of claim 1, wherein the piezoelectric fibers are uniaxially oriented and comprise crystals.   The transducer according to claim 1, wherein the conductive fiber is a metal-plated fiber.   The transducer according to claim 1, which is a woven or knitted fabric containing a plurality of the piezoelectric units and / or a plurality of the capacitance units.   The transformer according to claim 8, wherein the woven fabric contains a plurality of the piezoelectric units and / or a plurality of the capacitance units, and the woven structure is any of a plain weave, a twill weave, a satin weave, and a composite structure thereof. Deucer.   The transducer according to claim 9, wherein a plurality of the woven and knitted fabrics are used in combination.   The transducer according to any one of claims 1 to 10, amplification means for amplifying an electric signal output from the transducer in accordance with an applied pressure, and an electric signal amplified by the amplification means. An output means for outputting.   The device according to claim 11, further comprising a transmission unit that transmits the electrical signal output from the output unit to an external device. The transducer according to any one of claims 1 to 10,
Transmitting means for transmitting an electrical signal output from the transducer in response to an applied stress to an external device;
A device comprising:   A device comprising: receiving means for receiving an electric signal; and the transducer according to any one of claims 1 to 10 to which the electric signal received by the receiving means is applied.