CN117129021A - PVDF piezoelectric sensor device capable of realizing pressing and holding - Google Patents
PVDF piezoelectric sensor device capable of realizing pressing and holding Download PDFInfo
- Publication number
- CN117129021A CN117129021A CN202311032159.7A CN202311032159A CN117129021A CN 117129021 A CN117129021 A CN 117129021A CN 202311032159 A CN202311032159 A CN 202311032159A CN 117129021 A CN117129021 A CN 117129021A
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- piezoelectric sensor
- pvdf piezoelectric
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- 239000002033 PVDF binder Substances 0.000 title claims abstract description 45
- 229920002981 polyvinylidene fluoride Polymers 0.000 title claims abstract description 45
- 238000003825 pressing Methods 0.000 title claims abstract description 37
- 238000001514 detection method Methods 0.000 claims abstract description 21
- 239000003990 capacitor Substances 0.000 claims description 24
- 230000000149 penetrating effect Effects 0.000 claims description 21
- 239000012790 adhesive layer Substances 0.000 claims description 4
- 239000010410 layer Substances 0.000 claims description 4
- 230000006698 induction Effects 0.000 claims description 2
- 230000014759 maintenance of location Effects 0.000 claims 2
- 230000007774 longterm Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 3
- 230000001133 acceleration Effects 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention discloses a PVDF piezoelectric sensor device capable of realizing pressing and holding, which comprises a PVDF piezoelectric sensor for sensing pressing actions and a pressing detection and holding circuit for detecting the pressing and holding actions, wherein the PVDF piezoelectric sensor adopts a PVDF film sensor, is adhered to a surface to be detected, and is connected with and outputs sensing signals to the pressing detection and holding circuit. The invention performs slotting treatment on the operational amplifier and the pressing detection circuit so as to replace a feedback resistor and a pull-up resistor, and can avoid loss of electric charge converted from force, thereby realizing the pressing and holding functions. The problem that the piezoelectric sensor cannot realize signal detection of long-term pressing action for a long time is solved, so that the application field of the piezoelectric sensor, particularly the PVDF piezoelectric sensor, is greatly expanded.
Description
Technical Field
The invention relates to the field of piezoelectric sensors, in particular to a PVDF piezoelectric sensor device capable of realizing pressing and holding.
Background
The PVDF piezoelectric sensor is a film-shaped piezoelectric sensor with good flexibility, a piezoelectric crystal can convert input physical quantities such as force, displacement, acceleration and the like into electric charge quantity output, and the piezoelectric crystal sensor designed by the characteristic has wide application, such as acceleration measurement, vibration, object deformation, pressure and the like.
When the PVDF piezoelectric film sensor is subjected to external force in the vertical direction and is bent, corresponding strain voltage is output. There are also disadvantages to PVDF piezoelectric sensors, such as: the sensor effectively outputs a part of energy from the measured, the internal resistance of the sensor is high, and the output energy is smaller; at zero frequency, it is difficult to maintain a weak static charge for a long time, so its low frequency characteristic is poor, and it is generally only used for dynamic or near dynamic measurement; due to the polarization characteristics of the piezoelectric material, the piezoelectric system can only satisfy approximate linearity within a certain range and is easily affected by various external environments.
Therefore, the electric charges generated by the PVDF piezoelectric sensor can be acquired only after being changed into voltage signals through the charge amplifier, however, the signals generated by the PVDF piezoelectric sensor cannot be pressed and maintained by the traditional charge amplifier, so that the traditional charge amplifier needs to be modified, the loss of the electric charges converted from force needs to be avoided, and the function of pressing and maintaining is realized.
Disclosure of Invention
The invention aims to solve the technical problem of realizing a PVDF piezoelectric sensor device which modifies a traditional charge amplifier, performs slotting treatment on an operational amplifier and a pressing detection circuit so as to replace a feedback resistor and a pull-up resistor, avoids loss of converting force into charge and further realizes a pressing and holding function.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the PVDF piezoelectric sensor device capable of realizing pressing and holding comprises a PVDF piezoelectric sensor for sensing pressing action and a pressing detection holding circuit for detecting the pressing and holding action, wherein the PVDF piezoelectric sensor adopts a PVDF film sensor, the PVDF piezoelectric sensor is adhered to a surface to be detected, and the PVDF piezoelectric sensor is connected with and outputs an induction signal to the pressing detection holding circuit.
The PVDF piezoelectric sensor is adhered to the touch layer through the adhesive layer, and the non-touch pressed surface of the touch layer is adhered to the adhesive layer.
The pressing detection and holding circuit is composed of an operational amplifier unit U1, a feedback capacitor C1 and a bias capacitor C2 which are fixed on a PCB, wherein two ends of the feedback capacitor C1 are respectively connected with an inverting input end 4 and an output end 1 of the operational amplifier unit U1, one end of the bias capacitor C2 is connected with a non-inverting input end 3 of the operational amplifier unit U1, and the other end of the bias capacitor C2 is connected with Vref.
The input and output terminals of the operational amplifier unit U1 are respectively arranged at two sides of the packaging module.
The PCB circuit board is provided with a first penetrating slot, the position of the first penetrating slot is between the inverting input end 4 and the output end 1 of the operational amplifier unit U1, and the operational amplifier unit U1 spans the first penetrating slot and is fixed on the PCB circuit board.
The PCB is provided with a second penetrating type slot and a third penetrating type slot, the parameters of the first penetrating type slot, the second penetrating type slot and the third penetrating type slot are 13mm long and 1.5mm wide, and the three slots are parallel to each other;
two ends of the bias capacitor C2 are fixed on the PCB in a crossing way through the second penetrating slot; and two ends of the feedback capacitor C1 are fixed on the PCB in a crossing way through the third penetrating slot.
The parameters of the feedback capacitance C1 are determined by the size of the piezoelectric sensor surface area S, satisfying the formula c1=s·k, wherein
The bias capacitor C2 parameter is equal to the maximum value of the feedback capacitor C1.
The Vref parameter is equal to half the maximum output voltage of the operational amplifier unit U1.
The invention performs slotting treatment on the operational amplifier and the pressing detection circuit so as to replace a feedback resistor and a pull-up resistor, and can avoid loss of electric charge converted from force, thereby realizing the pressing and holding functions. The problem that the piezoelectric sensor cannot realize signal detection of long-term pressing action for a long time is solved, so that the application field of the piezoelectric sensor, particularly the PVDF piezoelectric sensor, is greatly expanded.
Drawings
The following is a brief description of what is expressed in each of the drawings in the specification of the invention:
FIG. 1 is a schematic illustration of PVDF piezoelectric sensor bonding;
FIG. 2 is a schematic diagram of the circuit principle;
FIG. 3 is a schematic diagram of a circuit board slotting process;
FIG. 4 is a schematic diagram of a long press signal waveform;
fig. 5 is a schematic diagram of a continuous short press signal waveform.
Detailed Description
The following detailed description of the embodiments of the invention, such as the shape and construction of the components, the mutual positions and connection relationships between the components, the roles and working principles of the components, the manufacturing process and the operating and using method, etc., is provided to assist those skilled in the art in a more complete, accurate and thorough understanding of the inventive concept and technical solution of the present invention.
PVDF piezoelectric sensor for sensing pressing motion and pressing detection holding circuit for detecting pressing holding motion. The signal detection of long-term pressing action is realized through the specially designed pressing detection holding circuit, and the function of rapid pressing detection is still maintained. The sensor for sensing the pressing action adopts a PVDF film sensor, the sensor needs to be firmly adhered to the surface to be detected, as shown in fig. 1, one surface of the pressing contact surface is used for being pressed by touch, the other surface is a surface pressed by non-touch, and the PVDF film sensor is adhered to the surface pressed by non-touch.
The PVDF piezoelectric sensor has two electrodes, one of which is a positive electrode and the other of which is a negative electrode, for receiving and transmitting a charge signal generated by a piezoelectric effect. When the sensor is subjected to pressure or force, a charge signal is generated between the positive and negative electrodes, which can be connected to a press detection holding circuit by wires, one end of each wire being connected to an electrode of the PVDF piezoelectric sensor, and the other end being connected to an input end of the press detection holding circuit, so that the charge signal generated by the sensor can be transmitted to the circuit for further processing.
The press detection holding circuit is composed of an operational amplifier unit U1, a feedback capacitor C1, and a bias capacitor C2, and a typical circuit schematic diagram thereof is shown in fig. 2. In particular, the circuit differs from the conventional circuit in that there is no feedback resistor R1 and no pull-up resistor R2.
The feedback capacitance C1 is chosen to be determined by the size of the PVDF piezoelectric sensor surface area S, i.e., to satisfy the equation c1=s·k, whereFor example, if PVDF piezoelectric sensor area s=280 mm 2 The rounding can be calculated according to the above formula to obtain the selected feedback capacitance C1 in the range of 120 pF-340 pF.
In the range of the value, a larger signal amplification factor can be obtained by selecting a smaller value of the feedback capacitor C1. For the bias capacitor C2, the value is equal to the maximum value of the feedback capacitor C1, which is 340PF in this example. Figure 2Vref has a value equal to half the maximum output voltage of the operational amplifier.
The feedback resistor R1 eliminated in fig. 2 is replaced by a through slot in the PCB circuit board, the slotted area of which is located between the inverting input 4 of U1 of fig. 1 and the output 1 of the op amp unit U1, and the feedback capacitor C1 should span over the slot. The eliminated pull-up resistor R2 is replaced by a through slot in the PCB circuit board whose slotted area is between Vref and the non-inverting input 3 of the op amp unit U1, and the bias capacitor C2 should span over the slot. Further, for selection of the operational amplifier unit U1, the operational amplifiers with input/output terminals on both sides of the package module should be selected. The PCB circuit board is provided with a first penetrating slot, the position of the first penetrating slot is between the inverting input end 4 and the output end 1 of the operational amplifier unit U1, and the operational amplifier unit U1 spans the first penetrating slot and is fixed on the PCB circuit board.
Specifically, three slots are respectively a first penetrating slot, a second penetrating slot and a third penetrating slot, the three slots are all 13mm long and 1.5mm wide, the three slots are parallel to each other, and two ends of the bias capacitor C2 are fixed on the PCB through the second penetrating slot; the two ends of the feedback capacitor C1 are fixed on the PCB through the third penetrating slot, the two ends of the operational amplifier unit U1 are fixed on the PCB through the first penetrating slot, the impedance matching property is realized through the PCB slot processing method, the functions of the feedback resistor and the pull-up resistor are achieved, noise interference can be reduced, and therefore the performance of the charge amplifier is improved.
The detection circuit can be used to keep the signal unchanged for long (one minute) compressions, a characteristic of which is shown in figure 4, and to detect in real time the signal that changes for rapid (ten seconds) compressions, a characteristic of which is shown in figure 5.
While the invention has been described above with reference to the accompanying drawings, it will be apparent that the invention is not limited to the above embodiments, but is capable of being modified or applied directly to other applications without modification, as long as various insubstantial modifications of the method concept and technical solution of the invention are adopted, all within the scope of the invention.
Claims (9)
1. The PVDF piezoelectric sensor device capable of realizing pressing and holding is characterized by comprising a PVDF piezoelectric sensor for sensing pressing action and a pressing detection holding circuit for detecting the pressing and holding action, wherein the PVDF piezoelectric sensor adopts a PVDF film sensor, the PVDF piezoelectric sensor is adhered to a surface to be detected, and the PVDF piezoelectric sensor is connected with and outputs an induction signal to the pressing detection holding circuit.
2. The pressure retention PVDF piezoelectric sensor device of claim 1, wherein the PVDF piezoelectric sensor is bonded to the touch layer by an adhesive layer, the non-touch pressed surface of the touch layer being bonded to the adhesive layer.
3. The PVDF piezoelectric sensor device according to claim 1 or 2, wherein the pressing detection holding circuit is composed of an operational amplifier unit U1 fixed on a PCB, a feedback capacitor C1, and a bias capacitor C2, wherein both ends of the feedback capacitor C1 are respectively connected to the inverting input terminal 4 and the output terminal 1 of the operational amplifier unit U1, and one end of the bias capacitor C2 is connected to the non-inverting input terminal 3 of the operational amplifier unit U1, and the other end is connected to Vref.
4. A PVDF piezoelectric sensor device according to claim 3, wherein the input and output terminals of the operational amplifier unit U1 are on both sides of the package module, respectively.
5. The PVDF piezoelectric sensor device according to claim 4, wherein the PCB is provided with a first through slot, the first through slot being located between the inverting input 4 and the output 1 of the op amp unit U1, the op amp unit U1 being fixed to the PCB across the first through slot.
6. The PVDF piezoelectric sensor device of claim 5, wherein the PCB is provided with a second through slot and a third through slot, the first through slot, the second through slot, and the third through slot are each 13mm long and 1.5mm wide, and the three slots are parallel to each other;
two ends of the bias capacitor C2 are fixed on the PCB in a crossing way through the second penetrating slot; and two ends of the feedback capacitor C1 are fixed on the PCB in a crossing way through the third penetrating slot.
7. The PVDF piezoelectric sensor device according to claim 1 or 6, characterized in that the feedback capacitance C1 parameter is determined by the size of the piezoelectric sensor surface area S, satisfying the formula c1=s·k, wherein
8. The pressure retention PVDF piezoelectric sensor assembly of claim 7, wherein the bias capacitance C2 parameter is equal to the maximum value of the feedback capacitance C1.
9. The pressure-retention-enabled PVDF piezoelectric sensor device according to claim 1, characterized in that the Vref parameter is equal to half the maximum output voltage of the operational amplifier unit U1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311032159.7A CN117129021A (en) | 2023-08-16 | 2023-08-16 | PVDF piezoelectric sensor device capable of realizing pressing and holding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311032159.7A CN117129021A (en) | 2023-08-16 | 2023-08-16 | PVDF piezoelectric sensor device capable of realizing pressing and holding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117129021A true CN117129021A (en) | 2023-11-28 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311032159.7A Pending CN117129021A (en) | 2023-08-16 | 2023-08-16 | PVDF piezoelectric sensor device capable of realizing pressing and holding |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117129021A (en) |
-
2023
- 2023-08-16 CN CN202311032159.7A patent/CN117129021A/en active Pending
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