Flexible tactile feedback electronic device and tactile feedback method

Abstract

The present invention discloses a flexible tactile feedback electronic device and a tactile feedback method, wherein the electronic device comprises an upper packaging layer, a flexible circuit layer and a lower packaging layer; the flexible circuit layer comprises an energy storage and control module, a flexible circuit board and a piezoelectric vibration array located in the upper layer, the control module is located on the upper surface of the flexible circuit board, the piezoelectric vibration array is located on the lower surface of the flexible circuit board, and the control module and the piezoelectric vibration array are connected through the electronic circuit of the flexible circuit board. The circuit control module decodes the vibration shape by acquiring the coding information, thereby controlling the vibration of the piezoelectric array in the lower layer, thereby realizing the tactile perception simulation of the object shape. The present invention adopts flexible piezoelectric material as a vibration generating source, and realizes energy storage through a wireless design module and a supercapacitor, which has significant advantages in flexibility and thickness, and opens up a new way to build an ultra-thin and high-resolution end-to-end flexible tactile wearable feedback device.

Description

Technical Field

[0001] The invention relates to tactile feedback, flexible electronics and flexible circuits, and in particular to a flexible tactile feedback electronic device, and also to a tactile feedback method based on the flexible tactile feedback electronic device. Background Art

[0002] The interactive feedback in existing virtual reality and augmented display technologies is mostly visual and auditory feedback. As one of the main ways for humans to perceive external information, touch conveys information that cannot be replaced by other senses, such as the texture and texture of objects, the sense of impact, etc. However, compared with eyes and ears, the feedback interaction of skin as a tactile interface in current commercial VR and AR technologies is almost completely ignored, and the lack of tactile feedback also leads to an incomplete user immersive experience. Therefore, how to perfectly integrate tactile feedback technology into human-computer interaction technologies such as VR and AR is an inevitable trend and technical requirement for future development.

[0003] At present, the research directions of tactile feedback technology are divided into: contact feedback and non-contact feedback. Among them, contact tactile feedback technology mostly adopts the principles of mechanical vibration, air pressure film, electrostatic force, etc., and uses gloves, arrays, air pressure film, screens and other interactive interfaces as tactile feedback interfaces. Due to the participation of air transmission media, non-contact tactile feedback requires more complex hardware structure and more sophisticated software algorithm to achieve focusing compared with contact tactile feedback. At the same time, its equipment is fixed in a certain position and cannot be moved. People can only feel tactile feedback when they enter the equipment. Therefore, for individuals, if they want to achieve whole-body tactile feedback, first, they need to build more complex and large equipment, and second, they need to further structure and optimize the mobile focusing algorithm. This makes non-contact tactile feedback technology have a natural disadvantage in cost and portability in building personal end-to-end VR / AR and other interactive devices.

[0004] In this regard, contact-type tactile feedback technology achieves full-body tactile feedback through the distributed arrangement and collaboration of multiple independent devices, and has great advantages in its construction on personal end-to-end VR / AR and other interactive devices. However, traditional contact-type tactile feedback technology mostly uses bulky, non-extensible mechanical devices such as gloves, arrays, and screens as interactive interfaces, which have great disadvantages in wearability and portability. Therefore, in order to realize personal end-to-end VR / AR and other interactive devices that are both functionally complete and comfortable to wear, research on more lightweight, miniaturized, wearable, and comfortable contact-type tactile feedback devices is a key technology that needs to be overcome.

[0005] The emergence and development of flexible electronic technology has provided a new device structure and working principle for the preparation of more wearable flexible tactile feedback devices. Flexible electronics are characterized by large area, variability, portability and multifunctional integration. In particular, for many disabled people with burns and amputations, skin-like flexible tactile feedback devices can be attached to the surface of functional devices such as prostheses in a form close to the skin, providing patients with corresponding tactile sensations while ensuring aesthetics, so as to ensure the normal life of patients. Therefore, combined with related technologies such as flexible electronic micro-nano manufacturing, the preparation of wearable flexible tactile feedback devices with skin-like characteristics and the exploration of their application in human-computer interaction technologies such as VR / AR have attracted widespread attention. Due to its inherent flexibility and extensibility, skin-like flexible wearable tactile feedback devices are also considered to be one of the most promising methods in personal VR / AR devices, which is expected to further innovate the concept of interaction in the fields of medicine, education, and military. Summary of the invention

[0006] Purpose of the invention: In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an ultra-thin and high-resolution end-to-end flexible tactile feedback electronic device. Another purpose of the present invention is to provide a tactile feedback method that can accurately perceive the shape of an object.

[0007] Technical solution: A flexible tactile feedback electronic device, comprising an upper packaging layer, a flexible circuit layer and a lower packaging layer; the flexible circuit layer comprises an energy storage and control module located on the upper layer, a flexible circuit board and a piezoelectric vibration array, the control module is located on the upper surface of the flexible circuit board, the piezoelectric vibration array is located on the lower surface of the flexible circuit board, and the control module and the piezoelectric vibration array are connected through the electronic circuit of the flexible circuit board.

[0008] Furthermore, the energy storage and control module includes a circuit control module, which is connected to the piezoelectric vibration array in the lower layer; the circuit control module obtains the shape of the object to be fed back through a wireless communication protocol, and controls the piezoelectric vibration array to vibrate in different modes for different shapes, thereby realizing tactile perception simulation of objects of different shapes.

[0009] Furthermore, the energy storage and control module also includes a wireless energy collection module and an energy storage module. The wireless energy collection module is connected to the energy storage module, and the energy storage module is connected to the circuit control module. The wireless energy collection module is composed of a power transmission coil, a power receiving coil and related circuit structures, and the wireless power supply of the circuit control module is realized by electromagnetic induction; wherein the power receiving coil is fixed on the flexible tactile feedback device, and the power transmission coil is an independent device. When the flexible tactile feedback device needs to be powered, the power transmission coil is brought close to the power receiving coil and a magnetic field signal is emitted at a certain frequency. According to the principle of electromagnetic induction, the power receiving coil will generate an alternating current signal of a certain frequency, and the four diodes in the power receiving coil form a rectifier circuit, which converts the alternating current signal into a fixed DC signal and supplies power to the flexible supercapacitor. The preferred energy storage module is a flexible supercapacitor to realize energy storage.

[0010] Furthermore, the circuit control module includes one or more SOC systems (system on chip), the SOC systems are powered by an energy storage module, and the lower layer of each SOC system is provided with a corresponding piezoelectric vibration array (23), and the piezoelectric vibration array (23) includes a plurality of piezoelectric units for simulating the tactile perception of objects of different shapes.

[0011] A method for object tactile feedback based on the flexible tactile feedback electronic skin, when the circuit control module includes a SOC system, includes the following contents:

[0012] (1) The SOC system obtains the encoded information of the vibration mode of the piezoelectric unit under a certain shape of object through a wireless communication protocol;

[0013] (2) According to the modified coded information, the SOC system controls the relevant piezoelectric units in its piezoelectric vibration array (23) to vibrate so as to produce corresponding tactile shapes on the skin.

[0014] A method for object tactile feedback based on the flexible tactile feedback electronic skin, when the circuit control module includes multiple SOC systems, includes the following contents:

[0015] (1) Under the constraints of the communication protocol, the decoding software of each SOC system decodes the vibration encoding information of the piezoelectric unit under the piezoelectric array controlled by it from the entire communication encoding information;

[0016] (2) Different SOC systems simultaneously control the vibration of their respective piezoelectric vibration arrays, wherein each SOC system controls the vibration of the corresponding piezoelectric units in the corresponding piezoelectric vibration array (23) of its lower layer in a time-sharing manner. All SOC systems cooperate to produce corresponding tactile shapes on the skin.

[0017] Preferably, the upper packaging layer is made of nanofiber textile material.

[0018] Preferably, the lower encapsulation layer is made of flexible organic high polymer.

[0019] Preferably, the piezoelectric material used to prepare the piezoelectric vibration array is an inorganic piezoelectric ceramic, a piezoelectric semiconductor, an organic piezoelectric material, a molecular ferroelectric material and a ferroelectric electret or a composite material with excellent piezoelectric properties.

[0020] The beneficial effects of the present invention are: 1. Flexible piezoelectric materials are used as vibration sources to provide excellent tactile feedback experience; 2. Energy storage is achieved through wireless design modules and supercapacitors, eliminating the need for complex charging equipment at the back end; 3. It has significant advantages in flexibility and thickness, which opens up a new way to build ultra-thin and high-resolution end-to-end flexible tactile wearable feedback devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the structure of a wirelessly powered flexible tactile feedback electronic device;

[0022] Figure 2 It is a schematic diagram of the structure of the energy storage and control module with wireless energy supply;

[0023] Figure 3 Schematic diagram of control for a single SOC control system implementing a "ten" shape. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described in detail below in conjunction with the embodiments and drawings.

[0025] like Figure 1 As shown, a wirelessly powered flexible tactile feedback electronic device of the present invention comprises an upper packaging layer 1, a flexible circuit layer 2 and a lower packaging layer 3. The flexible circuit layer 2 comprises an energy storage and control module 21 of an upper layer, a flexible circuit board 22 of an intermediate layer, and a piezoelectric vibration array 23 of a lower layer, wherein the energy storage and control module 21 is located on the upper surface of the flexible circuit board 22, the piezoelectric vibration array 23 is located on the lower surface of the flexible circuit board 22, and the energy storage and control module 21 and the piezoelectric vibration array 23 are connected through the electronic circuit of the flexible circuit board 22.

[0026] like Figure 2As shown, the energy storage and control module 21 includes a wireless energy collection module 211, an energy storage module and a circuit control module 212. The circuit control module includes one or more SOC systems (Moudle (1,1), Modle (1,2) ... Modle (N,N)) for controlling the vibration of the piezoelectric array. The SOC system is powered by the energy storage module, and the lower layer of each SOC system is respectively provided with a corresponding piezoelectric vibration array 23. For the Q×M piezoelectric vibration array, it includes multiple piezoelectric units (i, j), 1≤i≤Q, 1≤j≤M.

[0027] The circuit control module mainly realizes the following two functions:

[0028] 1. Objects of different shapes have different coding information. The circuit control module obtains the coding mode required by the shape of the object to be vibrated for feedback through the wireless communication protocol;

[0029] 2. Control the vibration mode of the piezoelectric vibration array on the lower layer to achieve tactile perception simulation of the object shape.

[0030] Specifically, the circuit control module obtains the code of the state of each piezoelectric unit under the corresponding shape of the object to be fed back. Specifically, the piezoelectric unit that needs to vibrate is coded as 1, and the piezoelectric unit that does not need to vibrate is coded as 0. After that, a sine wave signal of a certain frequency is output for the piezoelectric unit coded as 1 to realize the vibration of the piezoelectric unit. For the piezoelectric unit coded as 0, the output is fixed to 0V, so that it maintains its original state without vibration.

[0031] The wireless energy collection module 211 uses electromagnetic induction to realize wireless power supply, such as Figure 2 As shown, the wireless energy collection module consists of a power transmission coil, a power receiving coil and related circuit structures, wherein the power receiving coil is fixed on the flexible tactile feedback device, and the power transmission coil is an independent device. When the flexible tactile feedback device needs power supply, the power transmission coil is placed close to the power receiving coil and a magnetic field signal is emitted at a certain frequency. According to the principle of electromagnetic induction, the power receiving coil will generate an alternating current signal of a certain frequency, and the four diodes in the power receiving coil form a rectifier circuit, which converts the alternating current signal into a fixed DC signal and supplies power to the flexible supercapacitor. The energy storage module is a flexible supercapacitor to achieve energy storage.

[0032] When the circuit control module includes only one SOC system, the SOC system first obtains the coding information of the vibration mode of the piezoelectric unit under an object of a certain shape through a wireless communication protocol, and then controls the piezoelectric unit with the corresponding coding 1 in the piezoelectric vibration array corresponding to its lower layer to vibrate according to the changed coding information, thereby generating a corresponding tactile shape on the skin.

[0033] For complex-shaped objects or scenes with high-resolution requirements, the circuit control module includes multiple SOC systems. The communication protocol makes coding constraints for a certain specific-shaped object. The decoding software of each SOC system decodes the vibration coding information under its own piezoelectric array from the entire communication coding information; different SOC systems simultaneously control the vibration of the piezoelectric vibration arrays of their respective lower layers, wherein each SOC system controls the corresponding piezoelectric units with the corresponding code 1 in the piezoelectric vibration array 23 of its corresponding lower layer to vibrate in a time-sharing manner. All SOC systems work together to produce corresponding tactile shapes on the skin.

[0034] like Figure 3 As shown, taking a single SOC control system as an example, the tactile feedback process of the shape "ten" is described in detail:

[0035] 1. First, the wireless communication protocol inside the SOC system obtains the coding information required for the corresponding object shape "ten". For "ten", the code is 010111010. Even if PA_12, PA_21, PA_22, PA_23, PA_32 are coded as 1, vibration is required; while PA_11, PA_13, PA_31, PA_33 are coded as 0, no vibration is required.

[0036] 2. Then the SOC system controls the corresponding piezoelectric vibration units PA in the lower piezoelectric array to vibrate in a time-sharing manner. Figure 3 In the figure, the SOC system controls the PA units in the shaded part to vibrate (PA_12, PA_21, PA_22, PA_23, PA_32), thereby producing a corresponding tactile shape “10” on the skin.

[0037] The upper packaging layer 1 has electrical insulation, dust-proof function and air permeability, and is preferably made of nanofiber textile materials woven by electrostatic spinning technology, such as woven PVDF organic fiber materials. The flexible tactile feedback electronic device of the present invention can be used as electronic skin through wearable devices. At this time, the lower packaging layer 3 serves as a buffer layer between the piezoelectric vibration array 23 and the skin, and needs to have excellent vibration transmission performance, a Young's modulus similar to that of the skin, and electrical insulation properties (to avoid electrical leakage). It is preferably made of flexible organic polymers such as PVA.

[0038] Piezoelectric materials are used to prepare the piezoelectric units in the piezoelectric vibration array; the following is an analysis and demonstration of the factors for selecting piezoelectric materials:

[0039] As a functional structural unit, the choice of piezoelectric material determines the performance of the device's vibration, which in turn affects the tactile feedback experience. Since the entire device needs to be powered wirelessly, considering energy consumption and safety issues, the alternating voltage that provides the inverse piezoelectric effect should be limited to a lower state. From the formula S=d_33E, it can be obtained that under low voltage supply, the field strength of the electric field in which the piezoelectric material is located will decrease. Therefore, it is necessary to seek piezoelectric materials with high piezoelectric coefficients to produce larger displacements, thereby generating a vibrating sense of touch. On the other hand, relevant studies have shown that the human body is most sensitive to vibrations with a frequency between 100 and 300 Hz, so the frequency of the alternating voltage of the piezoelectric material should also be limited to this frequency. Therefore, it is necessary to find the optimal vibration frequency of the inverse piezoelectric effect of the piezoelectric material within the vibration frequency range of 100 to 300 Hz, and to study how to reduce the vibration hysteresis response time of the piezoelectric material. In addition, the device needs to have long-term vibration stability, so the piezoelectric coefficients of some basic piezoelectric materials such as ferroelectric electrets need to have long-term stability. Therefore, the piezoelectric material used in this device is inorganic ceramics, piezoelectric semiconductors, organic piezoelectric materials, molecular ferroelectric materials and ferroelectric electrets or composite materials with excellent piezoelectric properties, etc., and must also have the performance indicators mentioned above.

Claims

1. A flexible tactile feedback electronic device, characterized in that: The invention comprises an upper packaging layer (1), a flexible circuit layer (2) and a lower packaging layer (3); the flexible circuit layer (2) comprises an energy storage and control module (21), a flexible circuit board (22) and a piezoelectric vibration array (23); the control module (21) is located on the upper surface of the flexible circuit board (22); the piezoelectric vibration array (23) is located on the lower surface of the flexible circuit board (22); and the control module (21) and the piezoelectric vibration array (23) are connected via an electronic circuit of the flexible circuit board (22); The energy storage and control module (21) comprises a circuit control module, which is connected to the piezoelectric vibration array (23) at the lower layer; the circuit control module obtains the shape of the object to be fed back through a wireless communication protocol, and controls the piezoelectric vibration array (23) to vibrate in different modes for different shapes, thereby realizing tactile perception simulation of objects of different shapes.

2. The flexible tactile feedback electronic device according to claim 1, characterized in that: The energy storage and control module (21) further comprises a wireless energy collection module and an energy storage module for realizing wireless energy supply; the wireless energy collection module is connected to the energy storage module, and the energy storage module is connected to the circuit control module; The wireless energy collection module comprises a power transmission coil and a power receiving coil, and realizes wireless power supply by electromagnetic induction.

3. The flexible tactile feedback electronic device according to claim 2, characterized in that: The energy storage module is a flexible supercapacitor.

4. The flexible tactile feedback electronic device according to claim 1, characterized in that: The circuit control module comprises one or more SOC systems, the SOC systems are powered by an energy storage module, and the lower layer of each SOC system is provided with a corresponding piezoelectric vibration array (23), the piezoelectric vibration array (23) comprises a plurality of piezoelectric units, and is used to simulate the tactile perception of objects of different shapes.

5. The flexible tactile feedback electronic device according to claim 1, characterized in that: The upper packaging layer is made of nanofiber textile material.

6. The flexible tactile feedback electronic device according to claim 1, characterized in that: The piezoelectric vibration array (23) is made of inorganic piezoelectric ceramics, piezoelectric semiconductors, organic piezoelectric materials, molecular ferroelectric materials and ferroelectric electrets or composite materials with excellent piezoelectric properties.

7. The flexible tactile feedback electronic device according to claim 1, characterized in that: The lower packaging layer is made of flexible organic high molecular polymer.

8. A method for object tactile feedback based on the flexible tactile feedback electronic device as claimed in claim 4, characterized in that: When the circuit control module includes a SOC system, it includes the following contents: (1) The SOC system obtains the encoded information of the vibration mode of the piezoelectric unit corresponding to an object of a specific shape through a wireless communication protocol; (2) According to the coded information, the SOC system controls the relevant piezoelectric units in its piezoelectric vibration array (23) to vibrate so as to produce corresponding tactile shapes on the skin.

9. A method for object tactile feedback based on the flexible tactile feedback electronic device as claimed in claim 4, characterized in that: When the circuit control module includes multiple SOC systems, it includes the following contents: (1) Under the constraints of the communication protocol, the decoding software of each SOC system decodes the encoded information of the vibration mode of each piezoelectric unit from the entire communication encoded information; (2) Different SOC systems simultaneously control their respective piezoelectric vibration arrays to vibrate, wherein each SOC system controls the relevant piezoelectric units in its piezoelectric vibration array (23) to vibrate in a time-sharing manner; all SOC systems cooperate to produce corresponding tactile shapes on the skin.

Images