CN211602240U

CN211602240U - Electronic skin touch sensor device for flexible circuit board

Info

Publication number: CN211602240U
Application number: CN201922345274.5U
Authority: CN
Inventors: 袁江涛; 梁东兵
Original assignee: Advanced Electronic Zhuhai Co ltd
Current assignee: Advanced Electronic Zhuhai Co ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2020-09-29
Anticipated expiration: 2029-12-23

Abstract

The utility model relates to a tactile sensor device for flexible circuit board's electron skin, it includes tactile sensing array module, digital analog conversion module, MCU module, accumulator module and mains operated module. When the capacitive sensor is used, the touch sensing array module is used for acquiring a capacitance signal which causes micro deformation of a dielectric layer of the capacitive sensor unit or changes of a contact area of a polar plate due to external pressure or touch, the digital-to-analog conversion module converts the capacitance signal into a measured electric signal and transmits the measured electric signal to the MCU module for collection, control, processing and analysis actions and driving to control the on or off actions of corresponding electronic components. Compared with the flexible capacitive touch sensor in the prior art, the utility model discloses have the performance that improves electron skin, simple structure, the preparation is convenient.

Description

Electronic skin touch sensor device for flexible circuit board

[ technical field ] A method for producing a semiconductor device

The utility model relates to a tactile sensor device that is used for flexible circuit board's electron skin for PCB board technical field.

[ background of the invention ]

The appearance and development of electronic skin is inspired by biological skin perception, and in order for electronic skin to restore the function of biological skin, it is crucial to understand and mimic the properties affecting biological skin perception. The biological skin realizes the perception of external environment information through a receptor and then is sent to the central nervous system for comprehensive treatment. Biological skin receptors can be divided into seven major categories: pain receptors, cold receptors, warm receptors and four mechanoreceptors. Flexible sensors that differ in functional and performance requirements by understanding and studying the sensing mechanisms of biological service receptors and fine structure design. The flexible sensor is a combination of new materials, micro-electro-mechanical systems, nanotechnology, wireless technology, laser technology and the like. The biological skin receptor can sense tactile signals such as stress, pressure, shearing force and distortion, and external tactile signals with different quantizations are converted into electric signals which can be quantified by adopting an effective signal conduction method. The flexible capacitive touch sensor usually selects organic polymer materials such as polyethylene terephthalate (PET), Polydimethylsiloxane (PDMS), Polyimide (PI) and the like, and the organic polymer materials are prepared into a film with a pyramid-shaped or convex-shaped microstructure by using a complex film preparation process. Depositing a conductive coating on the film by using an electron beam evaporation or magnetron sputtering method, and preparing metal electrodes with different shapes by using a photoetching method. The flexible capacitive touch sensor can improve the performance of the electronic skin, such as pressure sensitivity, spatial resolution, and high tensile performance, but in some scenarios, throughput and design complexity.

[ Utility model ] content

In view of this, the present invention provides a touch sensor device for electronic skin of flexible circuit board, which can improve the performance of electronic skin, has a simple structure and is convenient to manufacture.

Therefore, the technical solution of the present invention is to provide a tactile sensor device for electronic skin of flexible circuit board, which comprises a tactile sensing array module, a digital-to-analog conversion module, an MCU module, a memory module and a power supply module; the output end of the touch sensing array module is connected with a digital-to-analog conversion module, the digital-to-analog conversion module is connected with an MCU module, the MCU module is connected with a storage module, and the storage module is connected with a power supply module; the MCU module comprises a flexible board, a central digital control module arranged on the flexible board, a switch array module arranged on the input end of the central digital control module, a plurality of capacitance sensing input interfaces connected to the switch array module, an excitation power supply connected with the capacitance sensing input interfaces, a signal correction module arranged at the output end of the central digital control module, a calibration memory module and a control data register which are arranged in parallel with the signal correction module; the power-on reset logic module is arranged in parallel with the excitation power supply, and the serial interface control logic module and the integrated control logic module are arranged at the other end of the flexible board; the serial interface control logic module is connected with the power-on reset logic module, and the integrated control logic module, the control data register and the calibration memory module are respectively connected between the serial interface control logic module and the power-on reset logic module; the capacitive sensing input interfaces are CIN 0-CIN 12 respectively; the MCU module is formed by a chip with the model of MPR121, and the working voltage of the chip is 1.71V to 3.6V; the supply current at the 16ms sampling interval period is 29 muA; a stop mode current of 3 μ Α; the 12 capacitive sensing input interfaces are 8 multifunctional inputs designed for the LED driver and GPIO.

Further, the power supply module includes a chip U1 with model MPR121, pins 1 to 20 disposed on the chip U1, a ceramic capacitor C1 disposed between pin 4 and pin 5, resistors R1 to R3 disposed between pin 1 to pin 3, and a resistor R4 disposed on pin 7.

Further, the tactile sensing array module includes a chip U2 with model number MPR121, a capacitor C2 disposed at a VSS terminal of the chip U2, a capacitor C3 disposed at a VREG terminal of the chip U2, resistors R5 to R7 disposed on the chip U2, a ground terminal disposed on the chip U2, and an analog-to-digital converter disposed on the chip U2.

Further, the tactile sensing array module comprises a conductive rubber device, an upper copper adhesive tape attached to the upper surface of the conductive rubber device, and a lower copper adhesive tape attached to the lower surface of the conductive rubber device.

The utility model has the advantages of: when the touch sensor device is used, the touch sensing array module is used for acquiring a capacitance signal caused by external pressure or touch to micro deformation of a dielectric layer of a capacitive sensor unit or change of a contact area of a polar plate, the digital-to-analog conversion module converts the capacitance signal into a measured electric signal and transmits the measured electric signal to the MCU module for collection, control, processing and analysis actions, and drives and controls the on or off actions of corresponding electronic components. Compared with the flexible capacitive touch sensor in the prior art, the utility model discloses have the performance that improves electron skin, simple structure, the preparation is convenient.

The technical solution of the present invention will be described in further detail with reference to the accompanying drawings and embodiments.

[ description of the drawings ]

Fig. 1 is a circuit diagram of a PCB circuit for protecting a switching power supply according to the present invention;

fig. 2 is a schematic circuit diagram of the switching voltage-reducing circuit of the present invention;

fig. 3 is a schematic circuit diagram of the power supply module of the present invention;

fig. 4 is a schematic circuit diagram of the middle touch sense sensor array module according to the present invention.

[ detailed description ] embodiments

In order to make the technical problem, technical solution and advantageous effects to be solved by the present invention clearer and more obvious, the following description of the present invention with reference to the accompanying drawings and embodiments is provided for further details. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 1 to 4, a tactile sensor device for electronic skin of a flexible circuit board is described below with reference to an embodiment, which includes a tactile sensing array module, a digital-to-analog conversion module, an MCU module, a memory module and a power supply module.

The touch sensing array module comprises a conductive rubber device, an upper copper adhesive tape attached to the upper surface of the conductive rubber device, and a lower copper adhesive tape attached to the lower surface of the conductive rubber device. The touch sensing array module further comprises a chip U2 with model of MPR121, a capacitor C2 arranged on a VSS end of the chip U2, a capacitor C3 arranged on a VREG end of the chip U2, resistors R5 to R7 respectively arranged on the chip U2, a grounding end arranged on the chip U2, and an analog-to-digital converter arranged on the chip U2. The resistance value of the conductive rubber device decreases with an increase in pressure.

The MCU module comprises a flexible board, a central digital control module arranged on the flexible board, a switch array module arranged on the input end of the central digital control module, a plurality of capacitance sensing input interfaces connected to the switch array module, an excitation power supply connected with the capacitance sensing input interfaces, a signal correction module arranged at the output end of the central digital control module, a calibration memory module and a control data register which are arranged in parallel with the signal correction module; the power-on reset logic module is arranged in parallel with the excitation power supply, and the serial interface control logic module and the integrated control logic module are arranged at the other end of the flexible board; the serial interface control logic module is connected with the power-on reset logic module, and the integrated control logic module, the control data register and the calibration memory module are respectively connected between the serial interface control logic module and the power-on reset logic module; the capacitive sensing input interfaces are CIN 0-CIN 12 respectively; the MCU module is formed by a chip with the model of MPR121, and the working voltage of the chip is 1.71V to 3.6V; the supply current at the 16ms sampling interval period is 29 muA; a stop mode current of 3 μ Α; the 12 capacitive sensing input interfaces are 8 multifunctional inputs designed for the LED driver and GPIO.

The power supply module comprises a chip U1 with model of MPR121, pins 1 to 20 arranged on the chip U1, a ceramic capacitor C1 arranged between pin 4 and pin 5, resistors R1 to R3 respectively arranged between pin 1 and pin 3, and a resistor R4 arranged on pin 7.

The VDD terminal and the VREG terminal are two power supply pins of a chip with model MPR 121. Since the Arduino Uno development board has a dc voltage output of 3.3V, we power the chip through the VDD terminal pin and have a 0.1uF ceramic capacitor between the power supply pin and the ground pin. The purpose of adding ceramic capacitors to the chip is to filter the power supply ripple, a noise ripple of more than 100mV may sometimes result in erroneous circuit function. The VDD terminal pin of the chip of the MPR121 is powered with a voltage ranging from 2.0V to 3.6V. Because the chip is internally integrated with the voltage regulating tube, the voltage regulating tube can regulate the voltage input from the pin at the VDD end to a lower value to the VREG end.

The capacitance measuring system is composed of a sensing electrode pad connected to a chip sensing input of the MPR12, and the chip and the Arduino Uno are connected through an I2C bus and an interrupt output. The chip of MPR121 has 12 sensing channels, and the capacitance on each sensing channel is composed of two parts, including the intrinsic capacitance of the chip electrode to ground and the capacitance to ground caused by finger touch. The chip adopts a constant direct current charging current scheme for measuring the capacitance, the capacitance of each sensing channel of the chip is charged, the charging period is T, the voltage of the electrode of the sensing channel of the chip is measured when the charging is finished, then the charge on the capacitance is released to the ground, and the discharging period is T.

The output end of the touch sensing array module is connected with a digital-to-analog conversion module, the digital-to-analog conversion module is connected with an MCU module, the MCU module is connected with a storage module, and the storage module is connected with a power supply module. The touch sensor module converts the change of the dielectric layer spacing or the contact area of the capacitance sensing unit caused by external pressure or touch into the change of capacitance, the digital-to-analog conversion module converts the capacitance change information on the sensing unit into an electric signal of voltage or current which can be measured, the MCU module finishes the control of the data acquisition process, and the storage module realizes the temporary storage processing of the acquired data.

The chip of MPR121 uses an I2C serial interface. The chip of MPR121 operates as a slave, which sends and receives data via an I2C interface. The I2C interface enables bidirectional communication between chips of Arduino Uno and MPR121 using a serial data line and a serial clock line. The Arduino Uno generates a serial clock synchronized with a data transfer process for controlling data transfer between the Arduino Uno and the chips of the MPR 121. The SDA line of the chip of MPR121 serves as both the input and the output with open drain, and the data line at the SDA end usually requires a pull-up resistance of 4.7k Ω. The SCL clock line of the chip of MPR121 serves as only one input, typically requiring a 4.7k Ω pull-up resistor. The I2C address of the chip of MPR121 may be implemented to be configurable. The I2C address is configurable by connecting pin ADDR of the chip of MPR121 to power, ground or the I2C interface pin, which is connected to the VSS terminal through pin ADDR.

When the chip of the MPR121 sends an interrupt request to the Arduino Uno, the Arduino Uno first sends a high-level to low-level signal as a start condition for data transmission to the capacitive touch sensor controller through the serial data line, followed by an I2C address of the capacitive touch sensor controller of 7bit, a read or write bit of data, a register address byte of the capacitive touch sensor controller of 8bit, and one or more data bits of 8 bit. When the Arduino Uno and the MPR121 complete data transmission, the Arduino Uno sends a low-level to high-level signal to the chip of the MPR121 as an end condition of the data transmission.

One data bit is transmitted between the chips of Arduino Uno and MPR121 for each clock pulse generated by Arduino Uno. When Arduino Uno puts the SCL terminal high, the data value on the SDA terminal line is in a steady state. When Arduino Uno sets the SCL terminal low, allowing the data on SDA to be modified to the reply signal, Arduino will pull the SDA terminal line high, which at this time will cause Arduino Uno to send a RESTART or STOP signal.

The detailed flow of the register is as follows: 1) the Arduino Uno sends a start condition signal to the chip of the MPR 121. The Arduino Uno sends an I2C address (7bit) and a write operation (1 bit) to the chip of the MPR121 and then waits for a chip acknowledge signal from the MPR 121. 3) The chip of the MPR121 sends a response signal to the Arduino Uno. 4) The Arduino Un sends an 8-bit register address to the chip of the MPR121, waiting for an acknowledgement signal from the chip of the MPR 121. 5) The chip of the MPR121 sends a response signal to the Arduino Uno. 6) The Arduino Uno sends 8-bit data to the chip of the MPR121, that is, writes the data into a register of the chip of the MPR121, and waits for a response signal. 7) The slave sends a reply signal. 8) By repeating the 6 th step and the 7 th step, data can be sequentially written into the plurality of registers of the MPR 121. 9) Arduino Uno initiates a stop signal to MPR 121.

The detailed flow of reading the chip data register of MPR121 by the I2C interface is as follows: 1) the Arduino Uno sends an I2C address of 7 bits and a write operation bit of 1bit to the chip of the MPR121, and waits for a response signal of the chip of the MPR 121. 2) The chip of the MPR121 sends a response signal to the Arduino Uno. 3) The Arduino Uno sends an 8-bit register address to the chip of the MPR121, and waits for a response signal from the chip of the MPR 121. 4) The chip of the MPR121 sends a response signal to the Arduino Uno. 5) Arduino Uno initiates the start condition. 6) The Arduino Uno sends a 7-bit I2C address and a 1-bit read operation, waiting for a reply signal from the chip of the MPR 121. 7) The chip of MPR121 transmits a response signal. 8) The chip of the MPR121 sends 8bit data to the Arduino Uno through the SDA end to the host. 9) The Arduino Uno sends a response signal to the chip of the MPR 121. 10) The 8 th step and the 9 th step may be repeated, and the values in the plurality of registers of the chip of the MPR121 are read sequentially.

The chip of the MPR121 functions as a capacitive touch sensing controller. The ELE0-ELE4 terminals of the chip of MPR121 are used to connect the 5 row electrodes of the capacitive sensor array and ELE5-ELE11 are used to connect the 7 column electrodes of the sensor array. The SCL and SDA terminals of the chip of the MPR121 are connected to the a5 and a4 terminals of the Arduino Uno, respectively, to enable I2C communication between the chip of the slave MPR121 and the master device (Arduino Uno). An interrupt pin (IRQ /) of the chip of the MPR121 is connected to a D2 digital pin of the Arduino Uno. The IRQ line, the SC line, and the SDA line of the chip of the MPR121 all require a pull-up resistance of 10k Ω to ensure that there is a certain high level on the IRQ line, the SC line, and the SDA line when the three lines are not connected to the chip of the Arduino Uno or the MPR 121. The chip of the MPR121 converts the capacitance signal of the capacitance sensing unit into a voltage signal, that is, the change of the capacitance of the sensing unit of the sensing array can be reflected in the collected voltage signal. The MPR121 chip has a 10bit analog-to-digital converter (i.e., a 10bit ADC) integrated therein, which can convert the analog voltage at the ADC input to a digital voltage in the range of 0-1023.

In summary, according to the technical scheme, the tactile sensor device is formed by the tactile sensing array module, the digital-to-analog conversion module, the MCU module, the storage module and the power supply module, when in use, the touch sensing alignment module is used to obtain a capacitance signal of a small deformation of the dielectric layer of the capacitive sensor unit or a change of the contact area of the electrode plate caused by external pressure or touch, and the digital-to-analog conversion module converts the capacitance signal into a measured electrical signal and transmits the measured electrical signal to the MCU module for collection, control, processing and analyzing, and driving to control the on or off operation of the corresponding electronic component. Compared with the flexible capacitive touch sensor in the prior art, the utility model discloses have the performance that improves electron skin, simple structure, the preparation is convenient.

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, without thereby limiting the scope of the invention. Any modification, equivalent replacement and improvement made by those skilled in the art without departing from the scope and spirit of the present invention should be within the scope of the claims of the present invention.

Claims

1. A touch sensor device for electronic skin of a flexible circuit board comprises a touch sensing array module, a digital-to-analog conversion module, an MCU module, a storage module and a power supply module; the method is characterized in that: the output end of the touch sensing array module is connected with a digital-to-analog conversion module, the digital-to-analog conversion module is connected with an MCU module, the MCU module is connected with a storage module, and the storage module is connected with a power supply module; the MCU module comprises a flexible board, a central digital control module arranged on the flexible board, a switch array module arranged on the input end of the central digital control module, a plurality of capacitance sensing input interfaces connected to the switch array module, an excitation power supply connected with the capacitance sensing input interfaces, a signal correction module arranged at the output end of the central digital control module, a calibration memory module and a control data register which are arranged in parallel with the signal correction module; the power-on reset logic module is arranged in parallel with the excitation power supply, and the serial interface control logic module and the integrated control logic module are arranged at the other end of the flexible board; the serial interface control logic module is connected with the power-on reset logic module, and the integrated control logic module, the control data register and the calibration memory module are respectively connected between the serial interface control logic module and the power-on reset logic module; the MCU module is formed by a chip with the model of MPR121, and the working voltage of the chip is 1.71V to 3.6V; the supply current under the condition of a 16ms sampling interval period is 29 muA; a stop mode current of 3 muA; the 12 capacitive sensing input interfaces are 8 multifunctional inputs designed for the LED driver and GPIO.

2. The electronic-dermatological tactile sensor apparatus for a flexible circuit board according to claim 1, wherein: the power supply module comprises a chip U1 with model of MPR121, pins 1 to 20 arranged on the chip U1, a ceramic capacitor C1 arranged between pin 4 and pin 5, resistors R1 to R3 respectively arranged between pin 1 and pin 3, and a resistor R4 arranged on pin 7.

3. The electronic-dermatological tactile sensor apparatus for a flexible circuit board according to claim 1, wherein: the touch sensing array module comprises a chip U2 with the model of MPR121, a capacitor C2 arranged on a VSS end of a chip U2, a capacitor C3 arranged on a VREG end of a chip U2, resistors R5 to R7 respectively arranged on a chip U2, a grounding end arranged on the chip U2 and an analog-to-digital converter arranged on a chip U2.

4. The electronic-dermatological tactile sensor apparatus for a flexible circuit board according to claim 1, wherein: the touch sensing array module comprises a conductive rubber device, an upper copper adhesive tape attached to the upper surface of the conductive rubber device, and a lower copper adhesive tape attached to the lower surface of the conductive rubber device.