JPH0871978A - Manipulator - Google Patents

Abstract

PURPOSE: To carry out positional control with a high degree of accuracy with a highly accurate sensor even though an actuator which has a low frictional resistance and is small-sized, which is made of shape memory alloy or chemomechanical gel, and which causes a large strain value. CONSTITUTION: A manipulator comprises a curved structure 11 composed of a plurality of hard parts 13 and soft flexible parts 14 provided between the adjacent hard parts 14, an actuator 15 for curving the soft parts, strain sensors 22 for drive control, attached to the structure and electrical connected, and a control circuit. The strain sensors 22 for drive control, are laid in the soft parts 14 of the curved structure 11, and the control circuit is arranged in the hard part 14, and the sensors 22 and the control circuit are connected together, electrically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bendable manipulator used in, for example, an endoscope.

[0002]

2. Description of the Related Art In recent years, attention has been focused on micromachine technology, and in particular, it is expected to apply this technology to industrial and medical microrobots and the like. For this purpose, it is essential to realize a micromanipulator for accessing the gripper or the like to any part. In this regard, various studies have been reported especially on silicon micromachining using LSI manufacturing technology.
Although many of them are related to micromanipulators, none of the actuators using silicon as a driving body is sufficient in the amount of deformation and the amount of generation.

On the other hand, as a micromanipulator using a shape memory alloy actuator which is excellent in displacement amount and generated force amount, there is known one disclosed in, for example, Japanese Patent Application Laid-Open No. 6-91582. This known example shows a manipulator in which each joint of a multi-joint structure having a link structure is integrated with an actuator, a strain sensor provided in the actuator, and a control circuit for controlling the strain sensor. Further, a manipulator using a chemo-mechanical gel actuator that is excellent in the amount of deformation is also known.

[0004]

However, the manipulator having the structure shown in the prior art is further miniaturized,
There are some problems in achieving high efficiency and high functionality. For example, in the case of a manipulator using a joint structure having a link structure as disclosed in Japanese Patent Laid-Open No. 6-91582, sliding frictional resistance of the link part becomes a problem, and the manipulator is generated particularly with miniaturization. Since the ratio of the sliding frictional resistance to the amount of force becomes large, there is a risk of hindering driving. Further, in a manipulator using an actuator that generates a large amount of strain such as shape memory alloy, when position control is performed by the strain sensor provided in the actuator, a large strain is also applied to the strain sensor, so a highly sensitive piezo Strain sensors such as resistance elements and pressure-sensitive diodes are difficult to apply because the ductility of semiconductors is low. In addition, a metal strain gauge using resistance change of a metal foil or the like has a small gauge factor, and thus it is difficult to measure strain with high accuracy.

Therefore, the present invention overcomes these problems, has a small frictional resistance, is small, and uses a high-precision semiconductor strain sensor while using an actuator that generates a large amount of strain such as a shape memory alloy or chemo-mechanical gel. It is an object of the present invention to provide a manipulator capable of performing highly accurate position control by using a strain sensor for drive control as described above.

[0006]

A manipulator according to the present invention includes a curved structure comprising at least two hard parts and a flexible soft part provided between the hard parts, and the soft part. A device that has a bending actuator, a drive control strain sensor that is arranged in the structure, and is electrically connected to each other and a control circuit, and that controls the drive of the actuator, and that supplies drive energy to the actuator. In the manipulator provided with an energy supply means for bending the soft part,
The drive control strain sensor is disposed in a flexible portion of the bending structure, and the control circuit is disposed in a rigid portion.

[0007]

In the manipulator according to the present invention,
By supplying energy to the actuator, the actuator causes the bending structure to bend at the flexible portion.
Then, the bending degree is detected by the drive control strain sensor, a signal corresponding to the detection signal is sent to the control circuit, and the energy supplied to the actuator is controlled by the control circuit. In this way, the bending structure is bent to a predetermined degree by controlling the feedback of the actuator.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a manipulator according to a first embodiment of the present invention will be described with reference to FIGS. This manipulator has an elongated cylindrical curved structure 11 having a through hole extending axially therethrough. This curved structure 11
Is a rigid part 13 and a flexible part 14 each having a circular cavity 12.
It has a configuration in which and are coaxially arranged alternately along the axial direction. That is, one soft part 14 is connected between two adjacent hard parts 13. In such a curved structure 11, the flexible portion 14 is made of a polymer material such as plastic having elasticity, but the flexible portion 14 may have a structure in which a member of a partially rigid portion is extended as a reinforcing material. good. In particular, as the soft portion 14, it is desirable to use an anisotropic stretchable material or the like which has a small amount of stretching in the circumferential direction and easily stretches in the horizontal direction. As such an anisotropic stretchable material, for example, a composite material in which a coil spring is embedded in a rubber-like polymer material is used. Also, the hard part 13
A metal structure formed by a method such as metal injection molding or a structure made of a material such as a resin that is not easily softened by heat, for example, a thermosetting resin is used. Further, in this structure 11, the hard part is formed of a resin having a high rigidity by the stereolithography method, and then the resin is replaced to form the soft part by the stereolithography method using a resin of a low rigidity. Can be manufactured using. This composite stereolithography method is disclosed in detail in, for example, Japanese Patent Laid-Open No. 7-60843.

At least one (two in the embodiment shown in FIG. 1) actuators 15 are arranged on the outer surface of the curved structure 11 so as to extend along the longitudinal direction of the structure 11. . The actuator 15 has a strip shape made of a shape memory alloy such as a TiNi alloy, and has a central portion provided on the flexible portion 14 so that both ends thereof extend from both ends of the flexible portion 14 toward the hard portion 13. Has been. This shape memory alloy is preliminarily subjected to an omnidirectional shape memory treatment in which bidirectional bending deformation is caused by a temperature change. Both ends of the actuator 15 are supported by support members 16 provided on the outer surface of the rigid portion 13. The support member 16 is formed in a plate shape whose center is separated from the surface of the hard portion 13 so that one end of the actuator 15 is inserted between the support member 16 and the outer surface of the hard portion 13. The end portion of the actuator 15 is supported by the support member 16 such that at least one end of the actuator 15 can move in the longitudinal direction with respect to the support member 16. This support member may be formed by attaching a member different from the curved structure to this, or by deforming a part of the structure.

When the shape memory alloy is used as the actuator as described above, the deformation amount and the deformation force of the actuator can be set to be large, so that the manipulator having the large bending deformation amount and the large deformation force can be controlled.

A tevice 17 is attached to the outer surface of the curved structure 11 by adhesion or heat welding. This device 17 is connected to a control circuit 21 formed inside or on the surface of a flexible thin film patterned into a predetermined shape, a drive control strain sensor 22, an electrothermal conversion element 25, and an external controller for operating a manipulator. Electrode pad 26 for wiring, and wiring 24 for electrically connecting these. This device 17
Is formed by the following process, for example.

First, a deep N-type diffusion layer forming an electronic circuit and a shallow N-type diffusion layer functioning as a semiconductor strain sensor are provided in a predetermined region of a P-type single crystal silicon substrate having a (100) plane orientation. Then, an electronic circuit having a CMOS structure is formed in the region of the deep N-type diffusion layer by using a normal semiconductor manufacturing technique. The deep N-type diffusion layer and the shallow N-type diffusion layer correspond to the electronic circuit 21 and the strain sensor 22 in FIG. 2, respectively.

Then, a silicon nitride film, which is an etching stopper layer for anisotropic silicon etching, is formed, and contact holes are formed by lithography in the film at locations corresponding to the control circuit 21 and the drive control strain sensor 22. To do.

Next, a polyimide film having a film thickness of 2 μm is formed on this, and a contact hole is formed at a necessary portion by a lithographic method. Thereafter, the wiring 24 made of aluminum or the like and the electrothermal conversion element 25 are formed on the polyimide film by a lithography method. Further, a polyimide film having a film thickness of 2 .mu.m is formed again thereon, and a contact hole is formed by a lithographic method at a portion of the polyimide film which will be the electrode pad 26. In this way, the flexible thin film 23 having an insulating property and formed of the polyimide film having the wiring 24 and the electrothermal conversion element 25 embedded therein is formed.

Finally, the electrode pad 26 made of aluminum or the like is formed on the flexible thin film 23 by a lithographic method. As described above, in the device 17 integrally formed on the silicon substrate, the N-type diffusion region in which the control circuit 21 and the drive control strain sensor 22 are formed is immersed in the anode and in an etching solution such as an aqueous potassium hydroxide solution. Using an electrochemical etching method that performs anisotropic etching while applying a voltage of several volts with the electrode such as platinum as a cathode,
Processing is performed to remove the silicon in the portion not protected by the N-type diffusion region and the silicon nitride film. Before performing this anisotropic etching, the surface side of the silicon substrate on which the flexible thin film 23, the wiring 24, the electrothermal conversion element 25, etc. are formed is protected from being attacked by the etching solution. A portion of the back surface of the substrate which is not subjected to anisotropic etching is protected by a silicon nitride film or the like.

After the anisotropic etching, the unnecessary etching stopper is removed by the reactive ion etching method or the like,
After that, the flexible thin film 23 is cut out from the silicon substrate,
A thinned device 17 is obtained.

As shown in FIG. 2, the flexible thin film 23 has a common straight line portion 23a and a first branch portion 23b branched from the middle of the straight line portion 23a in a direction orthogonal to and perpendicular to the common straight line portion 23a. And a second branch portion 23c. Each first branch portion 23b branches toward the support member 16 at the rigid portion 13 and is bent at a right angle at the support member 16 to reach the adjacent support member 16 on the flexible portion 14. Extending axially through. On the other hand, the second branch portion 23c branches at a substantially middle portion of the flexible portion 14, extends linearly for a predetermined length, and terminates at a central portion of the flexible portion 14. The wiring 24 includes a power line, a ground line, a signal line, which are formed by separating each line so as to insulate each other from each other.
And a synchronization signal line. This control circuit 2
1 is arranged as a circuit region in a deep N-type diffusion region selectively left by the above-described electrochemical etching at a branching point of the first branching section 23b on the common straight line section 23a. The details of this method are disclosed in JP-A-6-91582. On the other hand, the strain sensor 22 is a shallow N-type diffusion region that is selectively left by the above-mentioned electrochemical etching and is disposed at the end of the second branch portion 23c, and is a semiconductor strain gauge due to a piezoresistive effect. Function as. In addition, the electrothermal conversion element 25 extends under the actuator 15 and extends along the same, so that the first branch portion 23 is formed.
It is attached to the portion between the support members 16 of b. And
The electrode pad 26 is formed at one end of the common straight line portion 23a in the same manner as a normal semiconductor integrated circuit. Also,
This device 17 is provided with adhesive or heat welding at a plurality of points so as to have an appropriate slack when arranged in the curved structure so as not to be stretched or broken by the bending deformation of the manipulator. Fixed in the way. As the fixing portion, the region 25 of the electrothermal conversion element is adhered or welded to almost the entire front surface or the back surface of the actuator 15, and the control circuit 21 and its vicinity are entirely or partially attached to the rigid portion 14 of the curved structure. It is fixed by simple welding. Positionally flexible part 1
The region of the wiring 24 arranged along the line 3 is free from the curved structure while being supported at both ends corresponding to the rigid portion with appropriate slack, or is partially separated at some discrete points. Is glued or welded to. However, it goes without saying that the portion of the sensor 22 needs to be fixed to the flexible portion 14 by adhesion or welding in order to detect the bending amount of the manipulator. As the electrothermal conversion element 25, a metal material having superelasticity processed into a predetermined shape by using a semiconductor structure technology or the like is used so as not to be plastically deformed or broken by a large deformation amount of the shape memory alloy. Has been done. Further, this electrothermal converting element is arranged so as to be adhered to the actuator 15 as described above so that heat can be easily transmitted, but the soft portion of the bending structure 11 is affected by strain. In order to avoid this, it is preferable to arrange them separately.

The strain sensor 22 is electrically connected to the control circuit 21 by the wiring 24, and has an electrode pad 26.
A signal is transmitted to the controller of the manipulator connected to the, the bending angle of the manipulator is calculated from the strain amount of the strain sensor in the controller, and the feedback control of the actuator is performed.

The electrothermal converting element 25 is disposed below the actuator 15 and along with it, as described above, and is electrically connected to the control circuit 21 via the wiring 24. As a result, a current controlled by the control circuit 21 is supplied to the electrothermal conversion element 25 to generate heat, and the actuator 15 is bent to a degree corresponding to the supplied current value. In this way, the actuator 15 is arranged so as to be able to receive heat transfer to the electrothermal conversion element 25, and even if it is joined to the electrothermal conversion element 25, it can slide with respect to the electrothermal conversion element 25. It may be provided.

The operation of the manipulator having the above structure will be described below. First, the electrode pad 26 is connected to an external controller, and a power source (not shown) is turned on. As a result, electric power is applied from the external controller to the electrothermal conversion element 25 via the electrode pad 26 and the control circuit 21. The electrothermal conversion element 25 is heated by energization to transfer the heat to the actuator 15 made of a shape memory alloy, and when it is heated to the transformation temperature of the shape memory alloy or higher, the electrothermal conversion element 25 is bent and deformed into a shape that is memorized. Actuator 1 at this time
The deformation amount and the deformation force generated by
Is transmitted to the hard portion 13 and is further transmitted to the soft portion 14 via the hard portion 13, the soft portion 14 is deformed accordingly, and the manipulator is curved and deformed as shown in FIG. Further, due to the deformation of the soft portion 14, the drive control strain sensor 22 is strained, and the strain sensor 22 outputs an output signal corresponding to the strain to the control circuit 21. In response to the output of the strain sensor 22, the external controller sends a signal for controlling the electric power supplied to the electrothermal conversion element 25 to the control circuit 21, thereby performing feedback control such as controlling the bending angle of the actuator 15.

As described above, in this embodiment, since the manipulator is bent and deformed by the deformation of the flexible portion 14, there is no sliding resistance of the bent portion, and the actuator 1
It is possible to act on the bending operation of the manipulator without reducing the deformation amount and the deformation force generated in 5. Further, since the control circuit 21 is arranged in the rigid portion 13,
Since it is possible to avoid fluctuations in circuit characteristics due to deformation of the control circuit 21, it is possible to always perform normal control. Even in the actuator 15 using a shape memory alloy that generates a large amount of deformation, since the strain sensor 22 is arranged in the flexible portion 14, the strain applied is small and the semiconductor strain sensor 22 having high sensitivity can be used.

Naturally, each structure of this embodiment can be modified and changed in various ways. For example, in the drive control strain sensor 22, it is possible to use a plurality of semiconductor resistors to form a bridge circuit for enabling compensation such as temperature compensation.

Next, a manipulator according to the second embodiment of the present invention will be described with reference to FIG. The manipulator of this embodiment has substantially the same configuration as that of the first embodiment, but instead of the flexible portion 14 and the actuator 15, an electro-responsive chemo-mechanical gel 51 is used as a means that also serves as these. The chemo-mechanical gel 51 has a cylindrical shape having the same shape as the rigid portion 13 and is coaxially sandwiched between a pair of adjacent rigid portions 13. Further, two first branch portions 23b are formed in one control circuit 21 so as to extend in mutually opposite directions. Then, on the end portion of the first branch portion 23b, that is, on the chemo-mechanical gel 51, instead of the electrothermal conversion element 25, a strip-shaped electrode 52 for applying a voltage to this gel 51. Are electrically connected to the control circuit 21 and are attached so as to face each other. The electrodes 52 have a strip shape extending in the axial direction and are formed of a conductive thin film, for example, a platinum thin film. The electrode is preferably slidably arranged on the surface of the gel or on the surface layer so as not to hinder the deformation of the gel. The arrangement position of the electrodes is set so that the manipulator is bent and deformed. Also, preferably, as shown, one electrode 52
The drive control strain sensor 22 is disposed near the.

The electro-responsive chemo-mechanical gel is one that is deformed by an electric stimulus, for example, a copolymer of polyvinyl alcohol and sodium polyacrylate (P
VA-PAA) gel and poly-2-acrylamide ---
It is a polymer gel such as 2-methylprobansulfonic acid (PAMPS) gel, acrylonitrile gel, and acrylamide gel, and also includes ion exchange resins such as perfluorosulfonic acid and polyethylenesulfonic acid.

In the second embodiment, when a voltage is applied to the gel 51 from the electrode 52, the gel causes bending deformation and the manipulator bends.
As described above, according to this embodiment, the chemo-mechanical gel 51 serves as both the flexible portion of the curved structure and the actuator, so that the configuration is simplified and the size can be reduced. Further, since the chemo-mechanical gel has a large deformation amount, it is possible to increase the bending amount of the manipulator. Further, there is an effect that the responsiveness and controllability are good.

Next, a third embodiment of the present invention will be described.
Although not particularly shown, the manipulator of this embodiment has the following configuration. Although it has almost the same configuration as the first embodiment, the portion corresponding to the flexible portion 14 in FIG. 1 is made of a thermoresponsive chemo-mechanical gel, and this portion bends by heating and cooling. That is, since the flexible portion itself functions as an actuator, the portions corresponding to the actuator 15 and the support member 16 in FIG. 1 are unnecessary. In the present embodiment, a mechanism for heating the soft part made of a thermo-responsive chemo-mechanical gel is required to operate the actuator, which is a flexible thin film electrothermal conversion element shown in FIG. This can be easily achieved by arranging 25 so as to directly heat the flexible portion. Also in the present embodiment, as in the first embodiment, the bending angle of the manipulator is calculated from the strain amount of the sensor, and the actuator is feedback-controlled.

The thermoresponsive chemo-mechanical gel deforms in response to changes in heat, and is, for example, a polymer gel such as polyvinyl methyl ether (PVME) gel or N-substituted acrylamide gel.

The electrothermal converting element for heating the gel is one in which a metal material such as a superelastic material is processed into a predetermined shape by utilizing a semiconductor manufacturing technique or the like, and Joule heat is generated by energization. Is. The electrothermal conversion element is arranged on the surface or surface layer of the gel so as to be slidable so as not to hinder the deformation of the gel and to easily transfer heat.

In this embodiment, a controlled current is applied to the electrothermal conversion element which causes it to heat and heat the portion of the gel near the element to cause contractive deformation. Thus, the soft part made of this gel is bent and deformed in the direction in which the contraction deformation occurs. Further, by stopping the heating, the temperature of this gel is lowered, and accordingly, the gel is swollen and deformed to return to the original shape. In this way, the manipulator can be bent and deformed.

The manipulator of the third embodiment has the same effect as that of the second embodiment. Next, a fourth embodiment of the present invention will be described with reference to FIG.

In this embodiment, Except for the point that each flexible part 14 is provided with two drive control strain sensors,
Since it is substantially the same as the embodiment described above, only the differences will be described below.

In this embodiment, from the common straight line portion 23a,
Two second branch portions 23c are extended in parallel with each other with respect to one flexible portion 14. These second branch portions 23
c is suitable for extending along the axial front and rear portions of each flexible portion 14 (in the first embodiment, one second branch portion 23c extends substantially in the center of the flexible portion 14). It ends at a certain point. The strain sensors 22 are attached to the end portions of the second branch portions 23c, respectively. The strain sensor 22 is electrically connected to the control circuit 21 by a wiring 24 provided on the flexible thin film 23. It should be noted that the pair of strain sensors 22 provided on each wiring 24 are equivalent sensors, and only the arrangement positions are different, that is, one is axially forward and the other is axially rearward. Only.

As described above, since the pair of strain sensors 22 are arranged in each of the flexible portions 14, the manipulator of this embodiment receives the force from the outside, and when the flexible portion 14 is deformed, the same. The portion and the strength to which the external force is applied can be estimated from the strength difference and the magnitude of the strength of the output signals of the pair of strain sensors 22 arranged in the soft part. Therefore, drive control can be performed according to the influence of external force, and more accurate positioning can be performed.

The number of strain sensors 22 is not limited to two for each flexible portion 14. The more the strain sensors 22 are, the more accurately the bending can be controlled. However, the structure is complicated and the size is large. The number of strain sensors 22 may be appropriately selected according to the purpose of use.

Although the wiring 22 is omitted in FIGS. 4 and 5 showing the second and fourth embodiments, the same wiring as in FIG. 3 electrically connects the electric parts. For this purpose, the wiring is formed on the flexible thin film 23.

The curved structures according to the first to fourth embodiments described above are tubular and have a continuous cavity formed from the front end to the other end in the inside thereof, and have functional elements such as an optical fiber, a camera and a gripper. Can be inserted. As a result, a manipulator capable of accessing a desired part, such as a gripper inserted in the cavity, becomes possible. However, the curved structure of the present invention is not limited to a tubular structure, may be clogged, and the outer shape is not limited to a circular shape. For example, other shapes such as a rectangular shape and a filament shape are possible. You may be

Further, when the deformation directions of the actuators are arbitrarily set and arranged, each flexible portion can have a plurality of degrees of freedom. The drive control strain sensor is not limited to this, but a semiconductor strain sensor such as a piezoresistive element or a pressure sensitive diode that outputs an electric signal according to the strain due to the deformation of the soft portion is preferable. Since such a semiconductor strain sensor has a larger gauge factor than a metal strain sensor, the strain sensor can be directly arranged by a strain gauge because the strain sensor can be arranged at a soft portion instead of an actuator. A more accurate bending angle can be obtained.

In the curved structure, at least 2
If there are one hard portion and one soft portion provided between them, a predetermined bending function can be achieved, but by providing a plurality of soft portions, the bending deformation of the manipulator can be performed smoothly. . Further, the bending angle of the manipulator can be increased by deforming the respective soft parts in the same direction.

Although the present invention has been described based on the respective embodiments, the present invention is not limited to the above-mentioned embodiments, and various modifications and applications are possible within the scope of the gist of the present invention. .

Here, the summary of the present invention is summarized as follows. A manipulator according to a first aspect of the present invention includes a bending structure including at least two hard parts and a flexible soft part provided between the hard parts, and an actuator that bends the soft part. A device having a drive control strain sensor and a control circuit arranged in the structure and electrically connected to each other, the device controlling drive of the actuator, and the flexible portion for supplying drive energy to the actuator. In a manipulator having an energy supply means for bending
The drive control strain sensor is disposed in a flexible portion of the bending structure, and the control circuit is disposed in a rigid portion.

The first mode corresponds to all the drawings and has the following actions and effects. As the curved structure, the soft portion is made of a polymer material such as plastic having elasticity, but also includes a structure in which the hard portion is partially extended as a reinforcing member. In particular, it is preferable to use an anisotropic stretchable material or the like that has a small amount of stretch in the circumferential direction and is easily stretched in the horizontal direction as the soft portion.
The anisotropic stretchable material may be, for example, a composite material in which a coil spring is embedded in a rubber-like polymer material. For the hard part, a metal structure formed by a method such as metal injection molding or a resin structure that is not easily softened by heat, such as a thermosetting resin, is used.

The control circuit is arranged in the rigid part,
The drive control strain sensor is arranged in the flexible portion. The strain sensor is arranged at a portion of the soft portion that receives strain. Here, the strain sensor is fixed to the flexible portion by a method such as adhesion. By appropriately selecting the rigidity of the strain sensor and the flexible portion, the strain amount of the strain sensor with respect to the bending angle of the actuator can be optimized.

The actuator is not particularly limited as long as it has a deformation amount and a deformation force capable of deforming the flexible portion. By alternately arranging the hard portion and the soft portion as the bending structure, the deformation amount and the deformation force of the actuator act on the soft portion, and the soft portion is bent and deformed according to the deformation of the actuator.

Since the control circuit disposed in the rigid portion does not deform the rigid portion and thus does not distort the control circuit portion, the circuit characteristics do not change when the actuator is driven. Further, regarding the drive control strain sensor arranged in the flexible portion, the strain of the semiconductor strain sensor such as the piezoresistive element or the pressure sensitive diode is applied by the deformation of the flexible portion, and the strain amount can be measured. In this way, the strain sensor is connected to the control circuit, transmits a signal to the controller of the manipulator, calculates the bending angle of the manipulator from the strain amount of the strain sensor in the controller, and feedback-controls the actuator.

As described above, since the control circuit is arranged in the rigid portion, there is no change in the circuit characteristics due to the deformation of the control circuit portion, and the actuator can always be controlled normally. Furthermore, even when an actuator that generates a large amount of deformation is used, since the strain sensor is arranged in the soft portion, the strain applied can be reduced, so that a highly sensitive semiconductor strain sensor can be used. Further, since the strain sensor is arranged on the flexible portion itself, the strain of the flexible portion can be directly measured.

It is also possible to arrange a plurality of actuators for each soft part. When arranging a plurality of actuators, there is a configuration in which the deformation directions of the actuators are the same and the actuators are arranged in the structure, or a structure in which the deformation directions are arbitrarily set and arranged.

The manipulator according to the second aspect is the manipulator according to the first aspect, wherein the curved structure has three or more rigid portions and two or more flexible portions provided between adjacent rigid portions. The actuator, the drive control strain sensor, and the control circuit are provided corresponding to each flexible portion.

The second mode corresponds to all the embodiments shown in the drawings and has the following actions and effects. The plurality of actuators are arranged in the structure with the same deformation direction of each actuator, or arranged with the deformation direction set arbitrarily.

Since each of the plurality of flexible portions has an actuator, a strain sensor for drive control, and a control circuit, the deformation amount and the deformation force of the actuator act on the flexible portion for each flexible portion, and the flexible portion responds to the deformation of the actuator. The part is bent and deformed.

Further, the actuator is feedback-controlled by the signal of the strain sensor for each soft portion.
In this way, by having the plurality of soft portions, the bending deformation of the manipulator is smoothly performed. Further, the bending angle of the manipulator can be increased by deforming the respective soft parts in the same direction.

A manipulator according to a third aspect is the manipulator according to the first or second aspect, wherein the actuator has a shape memory alloy actuator whose both ends are respectively supported by two adjacent hard portions. Further, the energy supplying means has an electrothermal conversion element for heating the shape memory alloy actuator.

This third mode corresponds to the embodiment of FIGS. 1 to 3 and FIG. 5, and has the following actions and effects. The shape memory alloy actuator is made of, for example, a TiNi alloy or the like, and is supported by a material having elasticity in the longitudinal direction in addition to the support by the fixed support member provided in the rigid portion as shown in FIG. Alternatively, a method of inserting an actuator into a hole provided in the rigid portion may be used. This shape memory alloy actuator is supported by the indicating member so that both ends or one end can slide. Then, the shape memory alloy is subjected to an omnidirectional shape memory treatment that causes bidirectional bending deformation due to temperature change.

The electrothermal conversion element for heating the shape memory alloy actuator is made of a metal material having superelasticity by using a semiconductor structure technology or the like so as not to be plastically deformed or broken by a large deformation amount of the shape memory alloy. It is processed into a predetermined shape. In addition, this electrothermal converting element is arranged so as to be attached to or along the actuator 15 so that heat can be easily transmitted, and in order to avoid the influence of distortion due to the deformation of the soft portion, the curved structure 11 is provided. It is preferable that the flexible portion of the above-mentioned item is separated from the flexible portion.

By energizing the electrothermal converting element, Joule heat is generated to heat the shape memory alloy, and when the shape memory alloy reaches the transformation temperature, the shape memory alloy is transformed into the shape subjected to the shape memory treatment. Since the shape memory alloy is supported by the hard part, the deforming force and the amount of deformation generated by the shape memory alloy actuator are transmitted to the hard part, but the hard part is not deformed, so it is placed between the adjacent hard parts. The deforming force and the amount of deformation of the actuator act on the soft portion via the hard portion, and the soft portion is deformed.

Thus, since the shape memory alloy having a large deformation amount and a large deformation force can be used as the actuator, the manipulator having a large bending deformation amount and a large deformation force can be controlled. Further, the controllability is improved by using the electrothermal conversion element for heating the shape memory alloy.

A manipulator according to a fourth aspect is the manipulator according to the first or second aspect, characterized in that the hard portion and the soft portion of the curved structure are made of a photocurable resin. To do.

The fourth mode corresponds to all the embodiments shown in the drawings and has the following actions and effects. The hard portion and the soft portion of the curved structure are made of a photo-curable resin having different characteristics, and the hard portion and the soft portion are integrally molded by using a stereolithography method and a sacrifice layer etching technique. At the same time, the support member of the actuator may be integrally formed, or a portion where the wiring made of a flexible thin film is arranged may be partially recessed.

In the manipulator of this aspect, the deformation amount and the deformation force generated by the actuator act on the soft portion, and the soft portion deforms according to the deformation of the actuator, and causes the manipulator to bend and deform.

Thus, by integrally molding the curved structure composed of the soft portion and the hard portion by the optical molding method, the assembling process can be omitted, and a highly precise and small manipulator can be obtained.

A manipulator according to a fifth aspect is the manipulator according to the first or second aspect, wherein the soft portion is made of chemo-mechanical gel, and the chemo-mechanical gel constitutes the actuator. Characterize.

The fifth mode corresponds to the embodiment shown in FIG. 4 and has the following actions and effects. In this manipulator, the soft part is made of a chemo-mechanical gel, and the chemo-mechanical gel has a function of an actuator. That is, the relevant chemo-mechanical gel is subjected to heat change, pH change, ion concentration change, electrical stimulation,
By applying an external stimulus such as a light stimulus and a solvent conversion, the chemo-mechanical gel changes its shape such as swelling or contraction and acts as an actuator.

Thus, since the flexible portion has the function of the actuator, the structure is simplified and the size can be reduced. Further, since the chemo-mechanical gel has a large deformation amount, the bending amount of the manipulator can be increased.

A manipulator according to a sixth aspect is the manipulator according to the fourth aspect, wherein the soft portion is composed of an electro-responsive chemo-mechanical gel, and the energy supply means is the electro-responsive chemo-mechanical gel. It is characterized by having an electrode for applying a voltage to.

The sixth mode corresponds to the embodiment shown in FIG. 4 and has the following actions and effects. In this manipulator, the flexible portion of the bending structure is made of an electro-responsive chemo-mechanical gel and also serves as an actuator. The gel deforms in response to electrical stimulation, and for example, a copolymer of polyvinyl alcohol and sodium polyacrylate (PVA-PAA) gel or poly-2-acrylamido-2-methylprobansulfonic acid ( It is a polymer gel such as PAMPS) gel, acrylonitrile gel, and acrylamide gel, and also includes ion exchange resins such as perfluorosulfonic acid and polyethylene sulfonic acid.

The electrode for supplying the driving energy of the gel is made of a metal material such as platinum and is slidably arranged on the surface of the gel or on the surface layer so as not to hinder the deformation of the gel. The positions of the electrodes are set so that the manipulator is curved and deformed.

Thus, by applying a voltage to the electro-responsive chemo-mechanical gel, which is also the soft part and actuator, the gel is deformed according to the arrangement and polarity of the electrodes,
As a result, the manipulator is bent and deformed.

A manipulator according to a seventh aspect is the manipulator according to the fifth aspect, wherein the soft portion is composed of a thermoresponsive chemo-mechanical gel, and
The energy supply means has an electrothermal conversion element for heating the chemo-mechanical gel.

The seventh mode corresponds to the embodiment shown in FIG. 4 and has the following actions and effects. In this manipulator, the flexible part of the curved structure is
It consists of a thermo-responsive chemo-mechanical gel and doubles as an actuator. The gel deforms in response to changes in heat, for example, polyvinyl methyl ether (PVME)
Polymer gels such as gels and N-substituted acrylamide gels.

Further, the electrothermal conversion element for heating the corresponding gel is produced by processing a metal material such as a super elastic material into a predetermined shape by utilizing a semiconductor manufacturing technique or the like, and generating Joule heat when energized. The electrothermal conversion element is arranged on the surface or surface layer of the gel so as to be slidable so as not to hinder the deformation of the gel and to easily transfer heat.

When the soft portion is heated by the electrothermal converting element, the gel in the heated portion is stretched and deformed. For example, a high-temperature shrinkable gel shrinks. As a result, the manipulator is bent and deformed according to the deformation of the gel.

Thus, since the thermo-responsive chemo-mechanical gel also serves as the flexible portion of the curved structure and the actuator, the structure is simplified and the size can be reduced. A manipulator according to an eighth aspect is the manipulator according to any one of the above aspects, characterized in that the hard portion and the soft portion are tubular shapes connected to each other.

The eighth mode corresponds to all the embodiments shown in the drawings and has the following actions and effects. In this manipulator, the curved structure has a tubular shape and thus has a cavity.

As a result, in the cavity of the tubular curved structure,
Optical fibers and functional elements such as cameras and grippers can be inserted. As a result, the manipulator according to the ninth aspect, which enables a manipulator capable of accessing a desired part such as a gripper inserted in the cavity, is the manipulator according to any one of the aspects. A plurality of sensors are arranged in the flexible portion of the curved structure.

The ninth mode corresponds to the embodiment shown in FIG. 5 and has the following actions and effects. In this manipulator, in order to measure the amount of deformation of the soft part, a plurality of drive control strain sensors made of, for example, a semiconductor are arranged in the soft part.

By disposing a plurality of drive control strain sensors in the soft portion, the direction and site where the external force is acting can be estimated from the output signal of the strain sensor when a force is applied from the outside. If the number of strain sensors is large, the distribution of external force can be obtained. Also,
The magnitude of the external force can also be estimated by the strength of the output signal of the strain sensor.

In this way, since the strength of the external force exerted on the manipulator and the direction and site where the external force is acting can be estimated, drive control can be performed according to the influence of the external force, and more accurate positioning can be performed. it can.

The manipulator according to the tenth aspect is
In the manipulator according to any one of the above aspects,
The drive control strain sensor is a semiconductor strain sensor.

The tenth aspect corresponds to all the embodiments shown in the drawings, and has the following actions and effects. In this manipulator, the drive control strain sensor is a semiconductor strain sensor such as a piezoresistive element or a pressure sensitive diode.

The strain sensor for drive control arranged at the portion of the soft portion where the strain is applied applies strain to the strain sensor due to the deformation of the soft portion, and the strain amount is measured by the change in the resistance value of the semiconductor.

Since this semiconductor strain sensor has a larger gauge factor as compared with the metal strain sensor, the strain sensor can be directly arranged by the strain gauge because the strain sensor can be arranged not on the actuator but on the soft portion. , A more accurate bending angle can be obtained.

The manipulator according to the eleventh aspect is
In the manipulator according to any one of the above aspects,
The wiring is formed as a flexible thin film.

The eleventh aspect corresponds to all the embodiments shown in the drawings and has the following actions and effects. The wiring is protected from contamination and mechanical impact by the flexible thin film, and is electrically insulated from the curved structure.

The manipulator according to the twelfth aspect is
In the manipulator according to the first and second aspects, the drive control strain sensor and the control circuit are
It is integrally formed with the flexible thin film together with the wiring connecting them, and the wiring holding portion of this flexible thin film is separated from the curved structure, or several points are discrete. It is characterized in that it is partially attached by adhesion or welding.

The twelfth aspect corresponds to all the embodiments and has the following operational effects. The wiring part, which is integrally formed with the strain sensor and the control circuit on the flexible thin film, is separated from the curved structure or is separated by some adhesion or welding at some discrete points. Since it is worn, the structure is less likely to be distorted by the bending operation, and is less likely to be broken due to fatigue, so that stable control can be performed.

The manipulator according to the thirteenth aspect is
The manipulator according to the second aspect is characterized in that the flexible thin film is further integrally formed with the energy supply means.

The thirteenth mode corresponds to all the embodiments, and has the following operational effects. Since the strain sensor, the control circuit, the means for supplying energy to the actuator, and the wiring portion connecting them are integrally formed on the flexible thin film, the actuator drive control and the accompanying bending operation of the structure can be smoothly performed. it can.

[0087]

In the manipulator of the present invention, since the manipulator is bent and deformed by the deformation of the soft portion, by disposing the drive control strain sensor in the soft portion of the bending structure, The actuator can be controlled according to the deformation. Further, since the control circuit is arranged in the rigid portion, it is possible to avoid fluctuations in the circuit characteristics due to deformation of the control circuit, and always perform normal control. Even in an actuator using a shape memory alloy that generates a large amount of deformation, a strain sensor for driving control is arranged in the soft portion, so that the strain applied is small, and a strain sensor with high sensitivity such as a semiconductor strain sensor is used. Can be used.

[Brief description of drawings]

FIG. 1 is a perspective view showing a manipulator according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an expanded wiring used in the manipulator shown in FIG.

FIG. 3 is a perspective view showing a curved state of the manipulator shown in FIG.

FIG. 4 is a perspective view showing a manipulator according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a manipulator according to a fourth embodiment of the present invention.

[Explanation of symbols]

11 ... Curved structure, 13 ... Hard part, 14 ... Soft part, 15
... actuator, 21 ... control circuit, 22 ... drive control strain sensor, 24 ... wiring.

Claims (1)

[Claims] 1. A bending structure comprising at least two hard parts and a flexible soft part provided between the hard parts, an actuator for bending the soft part, and a bending structure arranged on the structure. A device having a drive control strain sensor and a control circuit electrically connected to each other, for controlling the drive of the actuator, and energy supply means for supplying drive energy to the actuator to bend the flexible portion. The manipulator comprising: the manipulator, wherein the drive control strain sensor is arranged in a soft part of the bending structure, and the control circuit is arranged in a hard part.