WO2013133514A1

WO2013133514A1 - Apparatus for providing texture with highly integrated, highly integrated-performance actuator, actuator array, and apparatus for providing tactile feedback

Info

Publication number: WO2013133514A1
Application number: PCT/KR2012/011251
Authority: WO
Inventors: Tae-Heon Yang; Yon-Kyu Park; Min Seok Kim; Sung Jun Lee; Han Wook Song; In-Mook Choi
Original assignee: Korea Research Institute Of Standards And Science
Priority date: 2012-03-09
Filing date: 2012-12-21
Publication date: 2013-09-12
Also published as: KR101303329B1

Abstract

The present invention relates to a highly-integrated surface texture providing apparatus, a highly-integrated high-performance tactile sense providing actuator, a highly-integrated high-performance tactile sense providing actuator array, and a tactile sense feedback apparatus. More specifically, the present invention relates to a highly-integrated high-performance tactile sense providing actuator, which can transfer both a delicate surface texture and a relatively high tactile sense to a user by generating both small and high displacements.

Description

APPARATUS FOR PROVIDING TEXTURE WITH HIGHLY INTEGRATED, HIGHLY INTEGRATED-PERFORMANCE ACTUATOR, ACTUATOR ARRAY, AND APPARATUS FOR PROVIDING TACTILE FEEDBACK

enerally, haptic is a tactile sense that can be felt through a fingertip of a person (the end of a finger or a stylus pen) when the person touches an object. It is a concept including tactile feedback that is felt when a skin touches on the surface of an object and kinesthetic force feedback that is felt when movements of joints and muscles are obstructed.

As sensory receptors of a human being, there are Pacinian corpuscle for sensing vibrations of a high frequency, Meissner's corpuscle for sensing vibrations of a low frequency, Merkel's disc for sensing locally applied pressures, and Ruffini's ending for sensing stretches pressing the skin. In order to reproduce a realistic tactile sense by stimulating such a variety of sensory receptors, the frequency bandwidth of an actuator is very important. Since the sensory receptors have different frequency ranges for activation, an actuator having a bandwidth of 250Hz or higher is needed to stimulate all of these sensory receptors.

In the prior art, a variety of actuators such as a solenoid actuator, a DC/AC motor, a servo motor, a ultrasonic actuator, a shape memory alloy ceramic actuator and the like satisfy the bandwidth of 250Hz or higher. A typical example of a tactile display apparatus is an apparatus for stimulating Pacinian and Meissner's corpuscles which sense vibrations of high/low frequencies by generating the vibrations using a vibration motor, according to an input of a touch screen at a mobile device.

However, in order to implement a realistic fine tactile sense, required is an actuator which can provide a bandwidth of some kHz, much higher than a bandwidth of 250Hz that can be distinguished by a human being. The Immersion Co. (immersion.com) has developed a high definition (HD) haptic device for providing a bandwidth of some kHz as a Piezo actuator having a high bandwidth in a mobile device. Although the Piezo actuator has a response speed as fast as about 1ms and thus has a high bandwidth, it may generate only a small displacement and is brittle, and thus it is difficult to mount the Piezo actuator on a portable device.

Contrarily, a dielectric polymer actuator proposed in the present invention has a rapid response speed to some extent, may generate a high displacement and is not brittle since it is formed of polymer, and thus it can be applied as a haptic actuator in a variety of electronic devices such as a portal device.

However, there is a limit in improving response speed due to the viscoelastic characteristic inherent to the dielectric polymer. Therefore, an actuator additionally including a restoring force generation unit for rapidly restoring the actuator is shown in the present invention in order to improve the limit of the response speed related to the viscoelastic characteristic. The restoring force generation unit can be configured using an elastic restoring force or a viscoelastic restoring force, and its progressiveness lies in configuring the restoring force generation unit to be compact.

The dielectric polymer actuator having a restoring force generation unit can be used as a high-performance vibration motor or a pin-array tactile display which can express a fine tactile sense, a protrusion and a shape to a user. In order to use the dielectric polymer actuator as the pin-array tactile display, a technique of integrating as many actuators as to simulate tactile sense of a human being in a small area is important. Therefore, it is an important factor to compactly design and insert the restoring force generation unit.

In order to implement the HD (High Definition) haptic device, an extremely large frequency bandwidth and a dense driver array having a high resolution are needed. Since there is a limit in configuring such an array in a conventional actuator design method, the present invention has devised an array of flexible electrodes which can express texture of the dielectric polymer.

FIG. 1 is a perspective view showing a dielectric polymer 1, and FIG. 2 is a perspective view showing a dielectric polymer 1 when voltage is applied to electrode layers 2. As shown in FIGs. 1 and 2, the operating principle of the dielectric polymer 1 is such that if the flexible electrode layers 2 are coated on the thin film dielectric polymer 1 and voltage is supplied, the thin film dielectric polymer 1 is modified to have a decreased thickness and an increased area.

In order to manufacture a driver of a tactile display apparatus 6 using the basic operating principle of the dielectric polymer 1 described above, horizontal deformation of the dielectric polymer 1 should be changed to vertical deformation.

As an example of the tactile display apparatus, Korean Patent Registration No. 718896 publicized on April 25 , 2007 discloses a display method implemented through deformation of the shape of adriving film, not a line tension method, insuggesting adriving direction by installing a frame 4 which fixes the outer portion of a dielectric polymer 1.

FIG. 3 is an exploded perspective view showing a dielectric-polymer-based driver 3 of the prior art, and FIG. 4 is a perspective view showing a dielectric-polymer-based driver 3 of the prior art. In addition, FIG. 5 is a perspective view showing a dielectric-polymer-based driver 3 of the prior art when voltage is applied to electrode layers 2, and FIG. 6 is a perspective view showing a tactile display apparatus 6 using a dielectric-polymer-based driver 3 of the prior art.

As shown in FIGs. 3, 4, 5 and 6, the dielectric-polymer-based driver 3 of the prior art includes a dielectric polymer 1 film, flexible electrode layers 2 respectively coated on the top and bottom surfaces of the dielectric polymer 1 film, a frame 4 for fixing the outer portion of the dielectric polymer 1 film, and protection films 5.

Accordingly, if voltage is applied to the electrode layers 2, the dielectric polymer 1 is expanded in the plane direction, and since the outer portion of the dielectric polymer 1 is restrained by the frame 4, it will protrude upward in the end as shown in FIGs. 5 and 6.

However, although the driver 3 and the tactile display apparatus 6 may increase the displacement of the vertical direction, a horizontal displacement is generated indirectly. Therefore, the normal force is only 13mN, and thus a relatively large force (normal force) cannot be generated. Furthermore, it is difficult to develop a highly integrated module, and wiring and control are difficult to perform. In addition, there is a limit in patterning a flexible electrode.

Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a tactile sense providing actuator, which can provide a user with a delicate surface texture by creating fine projections through a projection creation unit having a highly-integrated structure, and transfer both a delicate surface texture and a relatively high tactile sense to the user by providing a high-performance actuator having a vertical displacement and a normal force and thus simultaneously generating small and high displacements.

In addition, there is provides a high-performance tactile sense providing actuator which can improve restoring response speed by creating a restoring force through a restoring force generation unit in a direction opposite to a compressive force generated by a compressive force generation unit and increase a normal force by creating a magnetic force in a direction the same as that of the compressive force by including a magnetic force generation unit. In addition, there is provided a tactile sense feedback apparatus which can adjust the stimulus interval and the stimulus strength by adjusting the resonance frequency within the temporal acuity of human tactile sense.

The other objects, specific advantages and new features will be further clarified from the detailed descriptions and preferred embodiments shown below.

To accomplish the above objects, according to one aspect of the present invention, there is provided a highly-integrated surface texture providing apparatus comprising: a first electrode layer formed in a lattice shape and having flexibility; a second electrode layer symmetrical to the first electrode; and a dielectric polymer provided between the first electrode layer and the second electrode layer and compressed in a vertical direction by an applied voltage, wherein the dielectric polymer is compressed in the vertical direction at a portion contacting with the first electrode layer and the second electrode layer, and a portion that does not contact with at least one of the first electrode layer and the second electrode layer protrudes upward.

The second electrode layer is formed in a shape of a plane.

The apparatus further comprises a frame attached to an outer portion of a bottom surface of the dielectric polymer and restraining expansion of the dielectric polymer in a plane direction.

The apparatus further comprises protection films provided on a top and a bottom of the apparatus.

According to another aspect of the present invention, there is provided a tactile sense feedback apparatus comprising: the highly-integrated surface texture providing apparatus described above; a voltage supply unit provided in the highly-integrated surface texture providing apparatus, for supplying voltage to a first electrode layer and a second electrode layer; and a control unit for adjusting an interval of applying voltage to the first electrode layer and the second electrode layer by controlling the voltage supply unit.

According to another aspect of the present invention, there is provided a highly-integrated high-performance tactile sense providing actuator comprising: a projection creation unit including: a first electrode layer formed in a lattice shape and having flexibility; a second electrode layer symmetrical to the first electrode; a first dielectric polymer provided between the first electrode layer and the second electrode layer and compressed in a vertical direction by an applied voltage, and a frame attached to an outer portion of a bottom surface of the dielectric polymer and restraining expansion of the first dielectric polymer in a plane direction; and an actuating unit including: a housing provided below the projection creation unit and having flexibility; a second dielectric polymer provided on a top or a bottom of the housing, and expanded in a plane direction and compressed in a vertical direction by the applied voltage; and a compressive force generation unit having electrode layers installed on a top surface and a bottom surface of the second dielectric polymer, respectively.

The second electrode layer is formed in a shape of a plane.

The actuator further comprises a restoring force providing unit provided inside the housing of the actuating unit, for generating a restoring force corresponding to a compressive force generated by the compressive force generation unit.

The actuator further comprises protection films provided on a top and a bottom of the projection creation unit.

The compressive fore generation unit is provided in plurality as a stack.

The restoring force providing unit is provided on a top or a bottom of the compressive force generation unit and formed of an elastic member or the dielectric polymer.

The actuator further comprises: a permanent magnet provided between the compressive force generation unit and the restoring force generation unit; and ferromagnetic layers provided on an upper plate and a lower plate of the housing, respectively.

The actuator further comprises: a hole formed at a center of the upper plate of the housing and the compressive force generation unit provided in the actuating unit; and a contactor combined between the compressive force generation unit and the restoring force generation unit and repeatedly driven to protrude and retract inside the hall, wherein if voltage is applied to the second dielectric polymer through the electrode layers, the contactor protrudes upward by a compressive force, and the projection creation unit vertically elevates, and if the voltage is removed, the contactor retracts by a restoring force generated by the restoring force generation unit.

According to another aspect of the present invention, there is provided a highly-integrated high-performance tactile sense providing actuator array comprising: a plurality of the highly-integrated high-performance surface texure providing apparatus described above connected in a plane direction.

According to another aspect of the present invention, there is provided a tactile sense feedback apparatus comprising: the highly-integrated high-performance tactile sense providing actuator described above; a first voltage supply unit for supplying voltage to a first electrode layer and a second electrode layer provided in a projection creation unit of a highly-integrated high-performance surface texture providing apparatus; and a first control unit for adjusting an interval of applying voltage to the first electrode layer and the second electrode layer by controlling the first voltage supply unit.

In addition, the apparatus further comprises: a second voltage supply unit for supplying voltage to an electrode layer provided in an actuating unit of a highly-integrated high-performance surface texture providing apparatus; and a second control unit for adjusting an interval of applying voltage to the electrode layer by controlling the second voltage supply unit.

The second control unit controls strength and interval of tactile sense feedback by adjusting a voltage interval of a resonance frequency pulse, and the resonance frequency is within a temporal acuity of human tactile sense.

According to the embodiment of the present invention described above, there is provided provide a tactile sense providing actuator, which can provide a user with a delicate surface texture by creating fine projections through a projection creation unit having a highly-integrated structure, and transfer both a delicate surface texture and a relatively high tactile sense to the user by providing a high-performance actuator having a vertical displacement and a normal force and thus simultaneously generating small and high displacements.

In addition, there is provided a high-performance tactile sense providing actuator that can improve restoring response speed by creating a restoring force by a restoring force generation unit in a direction opposite to a compressive force generated by a compressive force generation unit and increase a normal force by creating a magnetic force in a direction the same as that of the compressive force by including a magnetic force generation unit. In addition, there is provided a tactile sense feedback apparatus that can adjust the stimulus interval and the stimulus strength by adjusting the resonance frequency within the temporal acuity of human tactile sense.

FIG. 1 is a perspective view showing a dielectric polymer.

FIG. 2 is a perspective view showing a dielectric polymer when voltage is applied to electrode plates.

FIG. 3 is an exploded perspective view showing a dielectric-polymer-based driver of the prior art.

FIG. 4 is a perspective view showing a dielectric-polymer-based driver of the prior art.

FIG. 5 is a perspective view showing a dielectric-polymer-based driver of the prior art when voltage is applied to an electrode plate.

FIG. 6 is a perspective view showing a tactile display apparatus using a dielectric-polymer-based driver of the prior art.

FIG. 7 is a perspective view showing a highly-integrated surface texture providing apparatus according to an embodiment of the present invention.

FIG. 8 is an exploded perspective view showing a highly-integrated surface texture providing apparatus according to an embodiment of the present invention.

FIG. 9 is a cross-sectional view showing a cell of a highly-integrated surface texture providing apparatus according to an embodiment of the present invention when voltage is not applied.

FIG. 10 is a cross-sectional view showing a cell of a highly-integrated surface texture providing apparatus according to an embodiment of the present invention when voltage is applied.

FIG. 11 is a partial cross-sectional view showing a highly-integrated surface texture providing apparatus according to an embodiment of the present invention when voltage is not applied.

FIG. 12 is a partial cross-sectional view showing a highly-integrated surface texture providing apparatus according to an embodiment of the present invention when voltage is applied.

FIG. 13 is a view showing a result of simulation using Ansys performed on a highly-integrated surface texture providing apparatus according to an embodiment of the present invention before voltage is applied.

FIG. 14 is a view showing a result of simulation using Ansys performed on a highly-integrated surface texture providing apparatus according to an embodiment of the present invention after voltage is applied.

FIG. 15 is an exploded perspective view showing a highly-integrated high-performance actuator according to a first embodiment of the present invention.

FIG. 16 is an exploded perspective view showing a highly-integrated high-performance actuator array according to a first embodiment of the present invention.

FIG. 17 is an exploded perspective view showing a highly-integrated high-performance actuator according to a second embodiment of the present invention.

FIG. 18 is a cross-sectional view showing a highly-integrated high-performance actuator according to a second embodiment of the present invention.

FIG. 19 is an exploded perspective view showing a highly-integrated high-performance actuator array according to a second embodiment of the present invention.

FIG. 20 is an exploded perspective view showing a highly-integrated high-performance actuator according to a third embodiment of the present invention.

FIG. 21 is a cross-sectional view showing a highly-integrated high-performance actuator according to a third embodiment of the present invention.

FIG. 22 is an exploded perspective view showing a highly-integrated high-performance actuator array according to a third embodiment of the present invention.

FIG. 23 shows graphs showing resonance frequencies and stimulus intervals in a tactile sense feedback apparatus applying a tactile sense providing actuator according to an embodiment of the present invention.

1: Dielectric polymer 2: Electrode layer

3: Conventional driver based on dielectric polymer

4: Frame 5: Protection film

6: Conventional tactile display apparatus

100: Highly-integrated surface texture providing apparatus

110: First electrode layer 120: Second electrode layer

130: Projection creation unit 200: Actuating unit

210: Compressive force generation unit

211: Upper compressive force generation unit

212: Lower compressive force generation unit

220: Restoring force providing unit

230: Contactor 241: Permanent magnet

242: Ferromagnetic layer

300: Highly-integrated high-performance tactile sense providing actuator

400: Highly-integrated high-performance tactile sense providing actuator array

T₁:Temporalacuityofhumantactilesense

T₂:Resonanceperiod T₃:Stimulusinterval

Hereinafter, the configuration and functions of a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention will be described. FIG. 7 is a perspective view showing a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention. In addition, FIG. 8 is an exploded perspective view showing a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention.

As shown in FIGs. 7 and 8, the highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention includes a dielectric polymer 1 expanded in the plane direction and compressed in the vertical direction when voltage is applied, a first electrode layer 110 of a mesh type combined on the top of the dielectric polymer 1, a second electrode layer 120 combined on the bottom of the dielectric polymer 1, and a frame 4 for fixing the outer portion of the dielectric polymer 1.

The first electrode layer 110 is formed in the shape of a mesh having a plurality of flexible horizontal and vertical lines configured in the form of a lattice. In the specific embodiment, the horizontal and vertical lengths of the first electrode layer are 2.5mm respectively, and the first electrode layer has one hundred cells, and thus the horizontal and vertical lengths of each cell are about 0.25mm respectively.

In addition, the outer portion of the dielectric polymer 1 is fixed by the flexible frame 4 attached to the outer peripheral portion of the bottom surface of the dielectric polymer 1, and the outer portion of the dielectric polymer 1 is restrained although voltage is applied.

In addition, the flexible second electrode layer 120 of a plate shape is combined on the bottom surface of the dielectric polymer 1. In the specific embodiment, the horizontal and vertical lengths of the second electrode layer of a plate shape are 2.5mm respectively. In addition, protection films 5 are combined on the top and bottom of the highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention. The protection films 5 are for insulation purpose and installed to prevent leakage of high voltage.

Accordingly, if voltage is applied to the first and second electrode layers 110 and 120 by a voltage supply unit, current flows through the dielectric polymer 1, and the portions contacting with the first electrode layer 110 are compressed in the vertical direction, and the portions that do not contact with the first electrode layer 110 are expanded in the vertical direction since the outer portion of the dielectric polymer 1 is restrained by the frame 4.

FIG. 9 is a cross-sectional view showing a cell of a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention when voltage is not applied, and FIG. 10 is a cross-sectional view showing a cell of a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention when voltage is applied.

FIG. 11 is a partial cross-sectional view showing a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention when voltage is not applied, and FIG. 12 is a partial cross-sectional view showing a highly-integrated surface texture providing apparatus 100 according to an embodiment of the present invention when voltage is applied.

As shown in FIGs. 10 and 12, if voltage is applied to the dielectric polymer 1 through the first and second electrode layers 110 and 120, the portions contacting with the first electrode layer 110 are compressed in the vertical direction since the outer portion of the dielectric polymer 1 is fixed by the frame 4, and the portions that do not contact with the first electrode layer 110 are pushed and inflated upward. Accordingly, fine projections are created on the top surface of the apparatus since the portions that do not contact with the mesh-type first electrode 110 are pushed and inflated and the portions contacting with the first electrode 110 are compressed. Accordingly, a user feels change of texture owing to the fine projections created on the highly-integrated surface texture providing apparatus 100.

FIG. 13 is a view showing a result of simulation using Ansys performed on a highly-integrated surface texture providing apparatus according to an embodiment of the present invention before voltage is applied, and FIG. 14 is a view showing a result of simulation using Ansys performed on a highly-integrated surface texture providing apparatus according to an embodiment of the present invention after voltage is applied. The physical properties of the dielectric polymer 1 used in the embodiment includes a compressive force of 2MPa, a Young’ modulus of 1.5Mpa and a Poisson’ ratio of 0.49. As shown in FIGs. 13 and 14, the portions contacting with the first electrode 110 form deep hollows. Accordingly, when the user actively touches the top surface, the user feels a tactile sense.

Hereinafter, the configuration and operation of the highly-integrated high-performance tactile sense providing actuator 300 according to an embodiment of the present invention will be described. The highly-integrated high-performance tactile sense providing actuator 300 according to an embodiment of the present invention is a combination of the high-performance tactile sense providing actuator 300 and the highly-integrated surface texture providing apparatus 100 described above.

That is, the highly-integrated high-performance tactile sense providing actuator 300 according to an embodiment of the present invention includes a projection creation unit 130 and an actuating unit 200 combined on the bottom of the projection creation unit 130, and since the projection creation unit 130 has a configuration the same as that of the highly-integrated surface texture providing apparatus 100 described above, details thereof will be omitted.

FIG. 15 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator 300 according to a first embodiment of the present invention. In addition, FIG. 16 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator array 400 according to a first embodiment of the present invention.

As shown in FIG. 15, the projection creation unit 130 provided on the top of the highly-integrated high-performance tactile sense providing actuator 300 according to a first embodiment of the present invention has a configuration the same as that of the highly-integrated surface texture providing apparatus 100 described above, and the actuating unit 200 provided on the bottom of the projection creation unit 130 has a configuration the same as that of the dielectric-polymer-based driver described in the background art.

As shown in FIGs. 3, 4, 5 and 6, the dielectric-polymer-based driver includes a dielectric polymer 1 film, flexible electrode layers 2 respectively coated on the top and bottom surfaces of the dielectric polymer 1 film, and a fixing frame 4 for fixing the outer portion of the dielectric polymer 1 film.

Accordingly, if voltage is applied to the electrode layers 2, the dielectric polymer 1 provided in the actuating unit 200 is expanded in the plane direction, and it will protrude upward as shown in FIGs. 15 and 16 in the end since the outer portion of the dielectric polymer 1 is restrained by the fixing frame 4. The horizontal and vertical lengths of the actuating unit 200 shown in FIG. 15 are about 2.5mm respectively.

In addition, the highly-integrated high-performance tactile sense providing actuator array 400 according to a first embodiment of the present invention shown in FIG. 16 is an array of 64 highly-integrated high-performance tactile sense providing actuators 300 shown in FIG. 15 which are connected in the plane direction. Accordingly, in the specific embodiment, the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator array 400 are about 20mm respectively, and the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator 300 are about 2.5mm respectively. The horizontal and vertical lengths of a cell provided in the projection creation unit 130 are about 0.25mm respectively.

Accordingly, the highly-integrated high-performance tactile sense providing actuator 300 generates both small and high displacements and transfers both a delicate surface texture and a relatively high tactile sense to a user.

FIG. 17 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator 300 according to a second embodiment of the present invention, FIG. 18 is a cross-sectional view showing a highly-integrated high-performance tactile sense providing actuator 300 according to a second embodiment of the present invention, and FIG. 19 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator array 400 according to a second embodiment of the present invention.

As shown in FIG. 17, the projection creation unit 130 provided on the top of the highly-integrated high-performance tactile sense providing actuator 300 according to a second embodiment of the present invention has a configuration the same as that of the highly-integrated surface texture providing apparatus 100 described above, and thus it will be described focusing on the actuating unit 200.

As shown in FIG. 18, the actuating unit 200 according to a second embodiment of the present invention includes a compressive force generation unit 210 combined on the bottom surface of the upper plate of a housing having flexibility, a restoring force providing unit 220 provided under the compressive force generation unit 210 and providing a restoring force, and a contactor 230 provided between the compressive force generation unit 210 and the restoring force providing unit 220.

The compressive force generation unit 210 includes a dielectric polymer 1 expanded in the plane direction and compressed in the vertical direction when voltage is applied and electrode layers 2 respectively combined on the top and bottom of the dielectric polymer 1, and the compressive force generation unit 210 is provided in plurality as a stack.

In addition, a hole having a predetermined diameter is formed on the top surface of the compressive force generation unit 210 and the housing, and the contactor 230 repeatedly driven to protrude and retract inside the hole is combined under the compressive force generation unit 210. The restoring force providing unit 220 is combined between the bottom of the contactor 230 and the lower plate of the housing and provides a restoring force. Accordingly, if voltage is applied to the compressive force generation unit 210, the dielectric polymer 1 is compressed in the vertical direction, and the contactor 230 protrudes upward. Then, the restoring force of the restoring force providing unit 220 is increased. Contrarily, if the voltage applied to the compressive force generation unit 210 is removed, the contactor 230 promptly retracts downward by the restoring force provided by the restoring force providing unit 220. Accordingly, the actuating unit 200 has a normal force and a vertical displacement relatively further larger than those of the projection creation unit 130.

In the specific embodiment, the horizontal and vertical lengths of the actuating unit 200 shown in FIG. 17 are about 2.5mm respectively. In addition, the highly-integrated high-performance tactile sense providing actuator array 400 according to a second embodiment of the present invention shown in FIG. 19 is an array of 64 highly-integrated high-performance tactile sense providing actuators 300 shown in FIG. 17 which are connected in the plane direction. Accordingly, in the specific embodiment, the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator array 400 are about 20mm respectively, and the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator 300 are about 2.5mm respectively. The horizontal and vertical lengths of a cell provided in the projection creation unit 130 are about 0.25mm respectively.

FIG. 20 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator 300 according to a third embodiment of the present invention, FIG. 21 is a cross-sectional view showing a highly-integrated high-performance tactile sense providing actuator 300 according to a third embodiment of the present invention, and FIG. 21 is an exploded perspective view showing a highly-integrated high-performance tactile sense providing actuator array 400 according to a third embodiment of the present invention.

As shown in FIG. 20, the projection creation unit 130 provided on the top of the highly-integrated high-performance tactile sense providing actuator 300 according to a third embodiment of the present invention has a configuration the same as that of the highly-integrated surface texture providing apparatus 100 described above, and thus it will be described focusing on the actuating unit 200.

As shown in FIG. 21, the actuating unit 200 according to a third embodiment of the present invention includes an upper compressive force generation unit 211 provided at an upper portion inside a housing having flexibility, a lower compressive force generation unit 212 provided at a lower portion inside the housing, a permanent magnet 241 provided between the upper compressive force generation unit 211 and the lower compressive force generation unit 212, and ferromagnetic layers 242 combined with the top and bottom plates of the housing.

The upper compressive force generation unit 211 and the lower restoring force providing unit 212 respectively include a dielectric polymer 1 expanded in the plane direction and compressed in the vertical direction when voltage is applied and electrode layers 2 respectively combined on the top and bottom of the dielectric polymer 1, and the upper and lower restoring

force providing units

211 and 212 are provided in plurality as a stack, respectively.

In addition, a hole having a predetermined diameter is formed on the top surface of the compressive force generation unit 211 and the housing, and a contactor 230 repeatedly driven to protrude and retract inside the hole is combined under the upper compressive force generation unit 211. In addition, a permanent magnet 241 is combined on the bottom surface of the contactor 230.

Accordingly, if voltage is applied to the upper compressive force generation unit 211, the dielectric polymer 1 provided in the upper compressive force generation unit 211 is compressed in the vertical direction, and the contactor 230 protrudes upward, and thus a restoring force is generated by the lower restoring force providing unit 212. In addition, the magnetic force is increased between the ferromagnetic layer 242 provided at the upper plate of the housing and the permanent magnetic 241 combined under the contactor 230. Accordingly, further larger normal force and vertical displacement are provided by the magnetic force.

In addition, if the voltage applied to the upper compressive force generation unit 211 is removed, the contactor 230 moves slightly downward, but maintains the protruded state. If voltage is applied to the lower restoring force providing unit 212, the dielectric polymer 1 provided in the lower restoring force providing unit 212 is compressed in the vertical direction, and the contactor 230 retracts downward. Therefore, a restoring force is generated by the upper compressive force generation unit 211, and in addition, the magnetic force is increased between the ferromagnetic layer 242 provided at the lower plate of the housing and the permanent magnetic 241 combined under the contactor 230. Accordingly, further larger normal force and vertical displacement are provided by the magnetic force, and the contactor 230 retracts further rapidly by the restoring force.

In the specific embodiment, the horizontal and vertical lengths of the actuating unit 200 shown in FIG. 20 are about 2.5mm respectively. In addition, the highly-integrated high-performance tactile sense providing actuator array 400 according to a third embodiment of the present invention shown in FIG. 22 is an array of 64 highly-integrated high-performance tactile sense providing actuators 300 shown in FIG. 20 which are connected in the plane direction. Accordingly, in the specific embodiment, the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator array 400 are about 20mm respectively, and the horizontal and vertical lengths of the highly-integrated high-performance tactile sense providing actuator 300 are about 2.5mm respectively. The horizontal and vertical lengths of a cell provided in the projection creation unit 130 are about 0.25mm respectively.

Hereinafter, the operation method of a tactile sense feedback apparatus applying the highly-integrated high-performance tactile sense providing actuator 300 will be described. The tactile sense feedback apparatus according to an embodiment of the present invention is provided with the highly-integrated high-performance tactile sense providing actuator 300 described above. In addition, the tactile sense feedback apparatus includes a first voltage supply unit for supplying voltage to the first and second electrode layers 110 and 120 of the projection creation unit 130 configuring the tactile sense providing actuator 300, a second voltage supply unit for supplying voltage to electrode layers 2 of the actuating unit 200, a first control unit for adjusting an interval of applying voltage to the electrode layers by controlling the first voltage supply unit, and a second control unit for adjusting an interval of applying voltage to the electrode layers by controlling the second voltage supply unit.

In addition, the first control unit and the second control unit adjust the voltage interval of a resonance frequency pulse within the temporal acuity of human tactile sense and control the strength and interval of the tactile sense feedback. That is, the temporal acuity of human tactile sense corresponds to 5.5ms. Accordingly, although a vibration stimulus is transferred several times within the temporal acuity of human tactile sense, a person feels the stimulus only once. However, if the vibration frequency is high within the temporal acuity of human tactile sense, i.e., the person is stimulated several times, although the person feels the stimulus only once, a higher output force is received in proportion to the number of stimuli. Accordingly, the control unit may control the strength of stimulus by adjusting the resonance frequency within the temporal acuity.

FIG. 23 shows graphs showing resonance frequencies (1/T₂,T₂: resonance period) and stimulus intervals T₃ in a tactile sense feedback apparatus applying a tactile sense providing actuator 300 according to an embodiment of the present invention. As shown in the first from the left in FIG. 23, if a person is stimulated three times within the temporal acuity T₁ of human tactile sense (i.e., the resonance period T₂ is one third of the temporal acuity T₁ of human tactile sense), the person feels the stimulus only once.

In addition, the first control unit and the second control unit may control the stimulus interval. That is, as shown in the second from the left in FIG. 23, it is possible to stimulate three time within the temporal acuity T₁ of human tactile sense, wait for a stimulus interval T₃ of 1 or 2 seconds, and then stimulate three time again within the temporal acuity T₁ of human tactile sense. In addition, the first control unit and the second control unit may control strength of stimulus. That is, as shown in the third from the left in FIG. 23, if a person is stimulated twice (the resonance period T₂ is a half of the temporal acuity T₁ of human tactile sense) within the temporal acuity T₁ of human tactile sense and stimulated four times (the resonance period T₂ is a quarter of the temporal acuity T₁ of human tactile sense) again within the temporal acuity T₁ of human tactile sense after a predetermined stimulus interval T₃, the person feels the stimulus twice, and the second stimulus will be further stronger than the first stimulus. The resonance frequency can be controlled within the temporal acuity T₁ of human tactile sense since a rapid response speed can be achieved by including the restoring force providing unit 220 and the magnetic force providing unit in the highly-integrated high-performance tactile sense providing actuating unit 200.

While the present invention has been described with reference to the particular illustrative embodiments, it is not to be restricted by the embodiments but only by the appended claims. It is to be appreciated that those skilled in the art can change or modify the embodiments without departing from the scope and spirit of the present invention.

Claims

A highly-integrated surface texture providing apparatus comprising:

a first electrode layer formed in a lattice shape and having flexibility;

a second electrode layer symmetrical to the first electrode; and

a dielectric polymer provided between the first electrode layer and the second electrode layer and compressed in a vertical direction by an applied voltage, wherein

the dielectric polymer is compressed in the vertical direction at a portion contacting with the first electrode layer and the second electrode layer, and a portion that does not contact with at least one of the first electrode layer and the second electrode layer protrudes upward.
The apparatus according to claim 1, wherein the second electrode layer is formed in a shape of a plane.
The apparatus according to claim 1, further comprising a frame attached to an outer portion of a bottom surface of the dielectric polymer and restraining expansion of the dielectric polymer in a plane direction.
The apparatus according to claim 1, further comprising protection films provided on a top and a bottom of the apparatus.
A tactile sense feedback apparatus comprising:

the highly-integrated surface texture providing apparatus of claim 1;

a voltage supply unit provided in the highly-integrated surface texture providing apparatus, for supplying voltage to a first electrode layer and a second electrode layer; and

a control unit for adjusting an interval of applying voltage to the first electrode layer and the second electrode layer by controlling the voltage supply unit.
A highly-integrated high-performance tactile sense providing actuator comprising:

a projection creation unit including:

a first electrode layer formed in a lattice shape and having flexibility;

a second electrode layer symmetrical to the first electrode;

a first dielectric polymer provided between the first electrode layer and the second electrode layer and compressed in a vertical direction by an applied voltage, and

a frame attached to an outer portion of a bottom surface of the dielectric polymer and restraining expansion of the first dielectric polymer in a plane direction; and

an actuating unit including:

a housing provided below the projection creation unit and having flexibility;

a second dielectric polymer provided on a top or a bottom of the housing, and expanded in a plane direction and compressed in a vertical direction by the applied voltage; and

a compressive force generation unit having electrode layers installed on a top surface and a bottom surface of the second dielectric polymer, respectively.
The actuator according to claim 6, wherein the second electrode layer is formed in a shape of a plane.
The actuator according to claim 6, further comprising a restoring force providing unit provided inside the housing of the actuating unit, for generating a restoring force corresponding to a compressive force generated by the compressive force generation unit.
The actuator according to claim 6, wherein further comprising protection films provided on a top and a bottom of the projection creation unit.
The actuator according to claim 6, wherein the compressive fore generation unit is provided in plurality as a stack.
The actuator according to claim 8, wherein the restoring force providing unit is provided on a top or a bottom of the compressive force generation unit and formed of an elastic member or the dielectric polymer.
The actuator according to claim 8, further comprising:

a permanent magnet provided between the compressive force generation unit and the restoring force generation unit; and

ferromagnetic layers provided on an upper plate and a lower plate of the housing, respectively.
The actuator according to claim 8 or 12, further comprising:

a hole formed at a center of the upper plate of the housing and the compressive force generation unit provided in the actuating unit; and

a contactor combined between the compressive force generation unit and the restoring force generation unit and repeatedly driven to protrude and retract inside the hall, wherein

if voltage is applied to the second dielectric polymer through the electrode layers, the contactor protrudes upward by a compressive force, and the projection creation unit vertically elevates, and if the voltage is removed, the contactor retracts by a restoring force generated by the restoring force generation unit.
A highly-integrated high-performance tactile sense providing actuator array comprising: a plurality of the highly-integrated high-performance surface texure providing apparatuses of claim 6 connected in a plane direction.
A tactile sense feedback apparatus comprising:

the highly-integrated high-performance tactile sense providing actuator of claim 6;

a first voltage supply unit for supplying voltage to a first electrode layer and a second electrode layer provided in a projection creation unit of a highly-integrated high-performance surface texture providing apparatus; and

a first control unit for adjusting an interval of applying voltage to the first electrode layer and the second electrode layer by controlling the first voltage supply unit.
The apparatus according to claim 15, further comprising:

a second voltage supply unit for supplying voltage to an electrode layer provided in an actuating unit of a highly-integrated high-performance surface texture providing apparatus; and

a second control unit for adjusting an interval of applying voltage to the electrode layer by controlling the second voltage supply unit.
The apparatus according to claim 16, wherein the second control unit controls strength and interval of tactile sense feedback by adjusting a voltage interval of a resonance frequency pulse, and the resonance frequency is within a temporal acuity of human tactile sense.