Abstract: A control device of a variable stiffness mechanism controls a total stiffness by variably outputting a voltage from a DC power source 10 to an “m” number of stiffness control elastomers 1 among a plurality of dielectric elastomers 1 of a variable stiffness mechanism 100. Further, in a state in which a square-wave signal is being output from a square-wave power source 11 to an “n” number of electrostatic capacitance estimation elastomers 1, a detection value of energizing current is acquired and the acquired detection value is used to estimate an electrostatic capacitance.

Abstract: A device capable of measuring the capacitance of a dielectric elastomer by variably manipulating the voltage applied to the dielectric elastomer includes a capacitance estimating unit that acquires current detection values at a plurality of sampling times in a current reduction period in which, when an output voltage of a power source changes, an energizing current of a dielectric elastomer increases and then gradually decreases according to the change in the output voltage, and estimates the capacitance of the dielectric elastomer on the basis of a model representing a correlation between the time-dependent change of the energizing current and the capacitance of the dielectric elastomer in the current reduction period, and the current detection values.

Abstract: Provided are an electrostrictive element comprising film electrodes that have a good elasticity and conductivity, and a manufacturing method therefor. Film electrodes 3 of an electrostrictive element 1 are sheet-shaped carbon nanotube aggregates 6, and can expand in the fiber direction while maintaining a state in which carbon nanotubes 7 overlap with each other, when the dielectric film 2 expands.

Abstract: An electrostrictive element that can prevent the breakage includes a current collector that is constituted by sheet-shaped carbon nanotube aggregates, and can expand in the fiber direction in a state in which carbon nanotubes overlap with each other, when a dielectric film expands.

Abstract: An actuator capable of preventing occurrence of insulation breakdown while achieving an appropriate operation performance of a dielectric elastomer is provided. Electrode films to be bonded to a dielectric elastomer are formed such that a characteristic of a change in thickness d of the elastomer with an increase in an applied voltage of the elastomer shows a first voltage range in which a decline rate of to the increase in is high and a second voltage range, including a voltage higher than the first voltage range, in which the decline rate of d to the increase in is low, and a voltage value at which the insulation breakdown of the elastomer occurs falls within the second voltage range.

Abstract: The present invention provides an electrostrictive element capable of preventing breakdown of a dielectric film. An electrostrictive element 1 includes a dielectric film 2 composed of an elastomer, a film electrode 3 formed inside a peripheral edge on at least one surface of the dielectric film 2 and capable of expanding and contracting so as to follow expansion and contraction of the dielectric film 2, and a frame 4 to keep the dielectric film 2 in an expansion state. The film electrode 3 includes portions 6, 7, 8 having a lower conductivity or a portion 9 having a higher rigidity than the other portion on a portion to be subjected to a greater total stress of a mechanical stress and an electrical stress than the other portion of the dielectric film 2.

Abstract: The present invention provides a spring mechanism which can elastically deform an elastic deformation part with a film shape of a transducer into a shape having high symmetry, and also can be structured in a small size. A spring mechanism 2 includes: a cylindrical member 7 that is provided so as to extend toward a first element member 21 from an elastic deformation part 11 of a transducer 5, and also is arranged so as to slidably penetrate the first element member 21 in the direction of a central axis line C of the elastic deformation part 11; and a rod member 32 that is provided so as to extend toward the cylindrical member 7 from a second element member 22 side, and is slidably inserted in the cylindrical member 7 in the direction of the central axis line C of the elastic deformation part 11.

Abstract: Provided is a method of manufacturing an electrostrictive element by which an electrostrictive element including an expandable and contradictable film electrode having a thin and uniform thickness can be easily formed. In a method of manufacturing an electrostrictive element 1, screen printing is performed while a first jig 12 contacts with a face of a dielectric film 2 opposite to a face where screen printing is performed such that the first jig 12 surrounds an area where the screen printing is performed. Thus, a film electrode 3 is formed.

Abstract: A present invention provides a device capable of properly measuring the capacitance of a dielectric elastomer by variably manipulating the voltage applied to the dielectric elastomer. A capacitance estimating unit 22 acquires current detection values at a plurality of sampling times in a current reduction period in which, when an output voltage of a power source 10 changes, an energizing current of a dielectric elastomer 1 increases and then gradually decreases according to the change in the output voltage, and estimates the capacitance of the dielectric elastomer 1 on the basis of a model representing a correlation between the time-dependent change of the energizing current and the capacitance of the dielectric elastomer 1 in the current reduction period, and the current detection values.

Abstract: A control device of a variable stiffness mechanism controls a total stiffness by variably outputting a voltage from a DC power source 10 to an “m” number of stiffness control elastomers 1 among a plurality of dielectric elastomers 1 of a variable stiffness mechanism 100. Further, in a state in which a square-wave signal is being output from a square-wave power source 11 to an “n” number of electrostatic capacitance estimation elastomers 1, a detection value of energizing current is acquired and the acquired detection value is used to estimate an electrostatic capacitance.

Abstract: A present invention provides a device capable of controlling a variable stiffness mechanism, which has a dielectric elastomer interposed between two members, so as to suppress an increase in the strain of the dielectric elastomer caused by the creep phenomenon. A power source control unit 21 corrects a reference supply voltage Vbase of an output voltage of a power source 10, which is determined on the basis of a desired degree of stiffness of a dielectric elastomer 1, by a feedback manipulated variable determined on the basis of a difference between a desired value of the capacitance of the elastomer 1 and an estimated value thereof, thereby setting a desired value for controlling the output voltage of the power source 10 in order to control the power source 10 according to the desired value for control.

Abstract: A control device 11 of a power transmission device 1 sets an allowable range of a temporal change rate of an inter-element driving force transmitted between a driving element 4 (elastic member) and a driven element 5 such that the allowable range changes in accordance with an observed value of the amount of elastic deformation of the elastic member (driving element 4), and controls the inter-element driving force, via an actuator 2, in such a way as to restrict the temporal change rate of the inter-element driving force to be within the allowable range thus set.

Abstract: Provided is an inexpensive conductive paste composition capable of forming an electrode having a sufficient expansion and contraction property and conductivity as an membrane electrode for use in an electrostrictive element. The conductive paste composition comprises an electrode-forming component, and a solvent in an amount of 10% to 70% by mass with respect to the electrode-forming component. The electrode-forming component comprises, with respect to the total amount of the solids content of the electrode-forming component, 2.5% to 4.7% by mass of a conductive carbon material, 54% to 68% by mass of silicone rubber, 0.05% to 0.2% by mass of a curing catalyst composed of a platinum-siloxane complex, and 16% to 30% by mass of silica.

Abstract: An actuator capable of preventing occurrence of insulation breakdown while achieving an appropriate operation performance of a dielectric elastomer is provided. Electrode films 3 to be bonded to a dielectric elastomer 2 are formed such that a characteristic of a change in thickness d of the elastomer 2 with an increase in an applied voltage V of the elastomer 2 shows a first voltage range ?1 in which a decline rate of d to the increase in V is high and a second voltage range ?2, including a voltage higher than the first voltage range ?1, in which the decline rate of d to the increase in V is low, and a voltage value Vmax at which the insulation breakdown of the elastomer 2 occurs falls within the second voltage range ?2.

Abstract: Provided is an electrostrictive element that can prevent the breakage. A current collector 5 of an electrostrictive element 1 is constituted by sheet-shaped carbon nanotube aggregates 6, and can expand in the fiber direction in a state in which carbon nanotubes 7 overlap with each other, when a dielectric film 2 expands.

Abstract: Provided is an inexpensive conductive paste composition capable of forming an electrode having a sufficient expansion and contraction property and conductivity as an membrane electrode for use in an electrostrictive element. The conductive paste composition comprises an electrode-forming component, and a solvent in an amount of 10% to 70% by mass with respect to the electrode-forming component. The electrode-forming component comprises, with respect to the total amount of the solids content of the electrode-forming component, 2.5% to 4.7% by mass of a conductive carbon material, 54% to 68% by mass of silicone rubber, 0.05% to 0.2% by mass of a curing catalyst composed of a platinum-siloxane complex, and 16% to 30% by mass of silica.

Abstract: Provided is a method of manufacturing an electrostrictive element by which an electrostrictive element including an expandable and contradictable film electrode having a thin and uniform thickness can be easily formed. In a method of manufacturing an electrostrictive element 1, screen printing is performed while a first jig 12 contacts with a face of a dielectric film 2 opposite to a face where screen printing is performed such that the first jig 12 surrounds an area where the screen printing is performed. Thus, a film electrode 3 is formed.

Abstract: The present invention provides a spring mechanism which can elastically deform an elastic deformation part with a film shape of a transducer into a shape having high symmetry, and also can be structured in a small size. A spring mechanism 2 includes: a cylindrical member 7 that is provided so as to extend toward a first element member 21 from an elastic deformation part 11 of a transducer 5, and also is arranged so as to slidably penetrate the first element member 21 in the direction of a central axis line C of the elastic deformation part 11; and a rod member 32 that is provided so as to extend toward the cylindrical member 7 from a second element member 22 side, and is slidably inserted in the cylindrical member 7 in the direction of the central axis line C of the elastic deformation part 11.

Abstract: Provided are an electrostrictive element comprising film electrodes that have a good elasticity and conductivity, and a manufacturing method therefor. Film electrodes 3 of an electrostrictive element 1 are sheet-shaped carbon nanotube aggregates 6, and can expand in the fiber direction while maintaining a state in which carbon nanotubes 7 overlap with each other, when the dielectric film 2 expands.

Abstract: The present invention provides an electrostrictive element capable of preventing breakdown of a dielectric film. An electrostrictive element 1 includes a dielectric film 2 composed of an elastomer, a film electrode 3 formed inside a peripheral edge on at least one surface of the dielectric film 2 and capable of expanding and contracting so as to follow expansion and contraction of the dielectric film 2, and a frame 4 to keep the dielectric film 2 in an expansion state. The film electrode 3 includes portions 6, 7, 8 having a lower conductivity or a portion 9 having a higher rigidity than the other portion on a portion to be subjected to a greater total stress of a mechanical stress and an electrical stress than the other portion of the dielectric film 2.