Piezoresistive sensor and sensor

Abstract

The invention provides a piezoresistive sensor and a sensor, the piezoresistive sensor can simulate the external pressure borne by a piezoresistive sensor structure through different voltages applied to a pressure simulation structure, and a processor calculates the resistance value of the piezoresistive sensor structure by adjusting the driving voltage of the piezoresistive sensor structure, so that the resistance value of the piezoresistive sensor structure is obtained. Therefore, excitation-response pairs required by the PUF technology are obtained. Comprising a power supply module, a processor, a storage module, an interface module and a piezoresistive sensor structure, the power supply module is used for supplying power to the processor, the storage module, the interface module and the piezoresistive sensor structure; the processor is electrically connected with the Wheatstone bridge structure; the piezoresistive sensor structure comprises a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used for simulating the change of external pressure borne by the piezoresistive sensor structure.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a piezoresistive sensor and a sensor. Background Art

[0002] PUF (Physically Unclonable Function) is a security technology based on the physical properties of hardware. It uses the tiny differences naturally occurring during the manufacturing process of the device to generate a unique and difficult-to-copy response to manage the identity of the hardware. The response of each PUF device is unique and cannot be accurately predicted or copied, which makes it important in the fields of the Internet of Things, embedded systems, and cloud computing.

[0003] In the related technology, PUF key technology has been used in some large mobile terminal devices, such as SRAM and DRAM. However, the existing technology lacks application in small devices such as MEMS sensors. Summary of the invention

[0004] One advantage of the present application is that it provides a piezoresistive sensor and sensor that can be applied with PUF key technology. By adjusting the voltage applied to the piezoresistive sensor structure through a pressure simulation structure, the magnitude of the external pressure on the piezoresistive sensor structure can be simulated, and by adjusting the driving voltage of the piezoresistive sensor structure, it can be used to generate the excitation-response pairs required by the PUF technology, thereby realizing the PUF key technology on the piezoresistive sensor.

[0005] Another advantage of the present application is to provide a piezoresistive sensor and a sensor, wherein in order to achieve the above advantages, no expensive materials or complex structures are required in the present application. Therefore, the solution provided by the present application can successfully and effectively solve the above problems, and not only provides a simple piezoresistive sensor and a sensor, but also increases the practicality and reliability of the piezoresistive sensor and a sensor.

[0006] Based on this, in order to achieve at least one of the above advantages or other advantages and purposes of the present application, the present application provides a piezoresistive sensor, including: a power module, a processor, a storage module, an interface module, and a piezoresistive sensor structure; the power module is used to provide power to the processor, the storage module, the interface module, and the piezoresistive sensor structure; the processor is electrically connected to the Wheatstone bridge structure, and is used to calculate the resistance value of the piezoresistive sensor structure, and is used to control the working state of the power module, and the processor is also used to control the voltage value of the driving voltage output by the power module to the piezoresistive sensor structure in response to a test signal of an external test device; the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the change of the external pressure to which the piezoresistive sensor structure is subjected;

[0007] Among them, when the piezoresistive sensor is in a testing state, the power module is electrically connected to the pressure simulation structure of the piezoresistive sensor structure, and when the piezoresistive sensor is in a working state, the power module is disconnected from the pressure simulation structure of the piezoresistive sensor structure.

[0008] With such a configuration, the piezoresistive sensor structure can simulate the magnitude of the external pressure applied to the piezoresistive sensor structure based on different voltages applied to the pressure simulation structure, and by adjusting the driving voltage of the piezoresistive sensor structure, the processor calculates the resistance value of the piezoresistive sensor structure, thereby obtaining the excitation-response pair required for the PUF technology.

[0009] According to one embodiment of the present application, the pressure simulation structure includes: a first pressure simulation electrode disposed at a diaphragm end of a cavity structure of the piezoresistive sensor structure;

[0010] A second pressure simulation electrode is disposed at a fixed end of the cavity structure of the piezoresistive sensor structure.

[0011] With such a configuration, since there is an attractive force between the two energized plates due to the electrostatic effect, the voltage difference between the first pressure simulation electrode and the second pressure simulation electrode can be adjusted to simulate the application of different pressures to the piezoresistive sensor structure, and the driving voltage of the piezoresistive sensor structure can be adjusted to generate the excitation-response pairs required for the PUF technology, and then the PUF key technology can be implemented on the piezoresistive sensor. Compared with the solution of directly applying pressure to the piezoresistive sensor structure, this solution applies different voltages on the surface of the cavity through the first pressure simulation electrode and the second pressure simulation electrode to simulate the application of different pressures to the piezoresistive sensor structure. Compared with the solution of applying pressure, the solution of applying voltage is easier to quantify and easier to reproduce.

[0012] According to one embodiment of the present application, the processor is used to control the connection and disconnection of the power module and the first pressure simulation electrode and the second pressure simulation electrode in response to a first test signal from an external testing device, and to control the potential and / or current applied by the power module to the first pressure simulation electrode and the second pressure simulation electrode.

[0013] With such a setting, the processor can be precisely controlled to ensure that the potential and / or current applied during the test is accurate and stable, thereby improving the accuracy and reliability of the test results; and the processor can also automatically respond to signals from external testing equipment to realize an automated testing process and improve the efficiency of the entire testing process.

[0014] According to one embodiment of the present application, the power supply module includes a battery, a first switch module, and a first voltage adjustment module. The first voltage adjustment module is electrically connected to the battery through the first switch module. The first switch module responds to a first test signal sent by the processor to turn on or off the connection between the first voltage adjustment module and the battery. The first voltage adjustment module responds to a first voltage signal sent by the processor to adjust the potential and / or current output to the first pressure simulation electrode and the second pressure simulation electrode.

[0015] In this way, after receiving the first voltage signal sent by the processor, the first voltage adjustment module adjusts the potential and / or current applied to the first pressure simulation electrode and the second pressure simulation electrode, thereby simulating the magnitude of the external pressure on the piezoresistive sensor structure, laying the foundation for the subsequent processor to calculate the resistance value of the piezoresistive sensor structure.

[0016] According to an embodiment of the present application, the first voltage adjustment module includes k first voltage output nodes, and a first resistor R1, a first resistor R2, ... a first resistor Rk connected in series in sequence, k is a positive integer, a first voltage output node is provided between two adjacent first resistors, and the first switch module is a k-to-2 selector;

[0017] One end of the battery is connected to the first pressure simulation electrode, and the other end is connected to the input end of the first resistor R1. The input end of the first resistor R1 is the first voltage output node 1. The input end of the k-to-2 selector is connected to the k first voltage output nodes through k second switch modules, and the output end of the k-to-2 selector is connected to the second pressure simulation electrode. The k-to-2 selector is used to respond to the first voltage signal of the processor and select the first voltage output node to be turned on.

[0018] With such arrangement, when it is necessary to apply different voltages to the pressure simulation structure of the piezoresistive sensor structure, different numbers of resistors can be connected according to different needs with the help of the voltage division principle, so that the voltages on different numbers of resistors can be applied to the pressure simulation structure of the piezoresistive sensor structure, thereby meeting the need to apply different voltages to the pressure simulation structure of the piezoresistive sensor structure. Compared with the solution using a sliding rheostat, this solution can automatically adjust the voltage output of the pressure simulation structure applied to the piezoresistive sensor structure with the help of hardware or software levels, which can reduce labor costs and improve test efficiency.

[0019] According to one embodiment of the present application, the power supply module also includes a third switch module and a second voltage adjustment module. The second voltage adjustment module is electrically connected to the battery through the third switch module. The third switch module responds to a second test signal sent by the processor to turn on or off the connection between the second voltage adjustment module and the battery. The second voltage adjustment module responds to a second voltage signal sent by the processor to adjust the voltage output to the piezoresistive sensor structure.

[0020] With such configuration, the processor can be used to control the second voltage adjustment module and the third switch module, thereby adjusting the driving voltage output to the piezoresistive sensor structure, that is, adjusting the voltage value of the electric energy supplied to the piezoresistive sensor structure.

[0021] According to an embodiment of the present application, the second voltage adjustment module includes n second voltage output nodes, and a second resistor R1, a second resistor R2, ... a second resistor Rn connected in series in sequence, n is a positive integer, and a second voltage output node is provided between two adjacent second resistors, and the third switch module is an n-to-2 selector;

[0022] One end of the battery is connected to the first input end of the driving voltage of the piezoresistive sensor structure, and the other end is connected to the input end of the second resistor R1, the input end of the second resistor R1 is the first second voltage output node, the input end of the n-to-2 selector is connected to the n second voltage output nodes through n fourth switch modules, the output end of the n-to-2 selector is connected to the second input end of the driving voltage of the piezoresistive sensor structure, and the n-to-2 selector is used to respond to the second voltage signal of the processor and select the second voltage output node to be turned on.

[0023] With such a configuration, when it is necessary to apply different voltages to the piezoresistive sensor structure, the voltage division principle can be used to connect different numbers of resistors according to different needs, so that the voltages on different numbers of resistors can be applied to the piezoresistive sensor structure, thereby meeting the need to apply different voltages to the piezoresistive sensor structure. Compared with the solution using a sliding rheostat, this solution can automatically adjust the voltage output applied to the piezoresistive sensor structure by means of hardware or software, which can reduce labor costs and improve test efficiency.

[0024] According to one embodiment of the present application, the power supply module also includes a fifth switch module and a sixth switch module, the first end of the sixth switch module is connected to the positive electrode V+ of the output voltage of the piezoresistive sensor structure, and the second end is grounded; the first end of the fifth switch module is connected to the negative electrode V- of the output voltage of the piezoresistive sensor structure, and the second end is grounded; the sixth switch module is closed in response to the output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the fifth switch is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

[0025] With such an arrangement, the fifth switch module can be closed or closed in response to the output voltage test signal of V- or V+, and the sixth switch module can be closed or closed in response to the output voltage test signal of V- or V+, so as to accurately measure the voltage applied to the piezoresistive sensor structure at a certain moment. Compared with directly measuring the voltage output to the piezoresistive sensor structure, this scheme can effectively eliminate the system errors caused by power supply voltage fluctuations, resistance temperature coefficient, etc., improve the measurement accuracy, and can effectively reduce the influence of external electromagnetic interference on the measurement results, so as to improve the accuracy of the measurement of the voltage applied to the piezoresistive sensor structure at a certain moment.

[0026] According to one embodiment of the present application, the piezoresistive sensor is a MEMS / NEMS pressure sensor, a MEMS / NEMS force sensor, a MEMS / NEMS acceleration sensor, a MEMS / NEMS displacement sensor, a MEMS / NEMS strain sensor, a MEMS / NEMS flow sensor, or a MEMS / NEMS torque sensor.

[0027] According to another aspect of the present application, the present application further provides a sensor, including a power module, a processor, a storage module, an interface module, and a piezoresistive sensor structure; the power module is used to provide power for the processor, the storage module, the interface module, and the piezoresistive sensor structure; the processor is electrically connected to the Wheatstone bridge structure of the piezoresistive sensor structure, and is used to calculate the resistance value of the piezoresistive sensor structure, and is used to control the working state of the power module, and the processor is also used to control the voltage value of the driving voltage output by the power module to the piezoresistive sensor structure in response to a test signal of an external test device; the power module includes a battery, a third switch module, and a second voltage adjustment module, the second voltage adjustment module is electrically connected to the battery through the third switch module, the third switch module switches on or off the connection between the second voltage adjustment module and the battery in response to a second test signal sent by the processor, and the second voltage adjustment module adjusts the voltage value output to the piezoresistive sensor structure in response to a second voltage signal sent by the processor;

[0028] Among them, when the sensor is in a testing state, the third switch module turns on the connection between the second voltage adjustment module and the battery, and when the sensor is in a working state, the third switch module disconnects the connection between the second voltage adjustment module and the battery, and the battery directly powers the piezoresistive sensor structure.

[0029] In this configuration, the sensor applies a driving voltage with different voltage values ​​adjusted to the piezoresistive sensor structure and calculates the resistance value of the piezoresistive sensor structure with the aid of the processor, thereby obtaining the excitation-response pair required by the PUF technology.

[0030] Beneficial effect: The piezoresistive sensor disclosed in the embodiment of the present application supplies power to the processor, storage module, interface module, and piezoresistive sensor structure through the power module, and switches between a test state and a working state with the help of the processor. In the working state, the processor controls the power module to be disconnected from the pressure simulation structure of the piezoresistive sensor structure so that the piezoresistive sensor works normally. In the test state, the processor controls the power module to be electrically connected to the pressure simulation structure of the piezoresistive sensor structure, and the processor also controls the voltage value of the driving voltage output by the power module to the piezoresistive sensor structure in response to a test signal of an external testing device, and can simulate the size of the external pressure on the piezoresistive sensor structure based on different voltages applied to the pressure simulation structure according to the piezoresistive sensor structure, and by adjusting the driving voltage of the piezoresistive sensor structure, the processor calculates the resistance value of the piezoresistive sensor structure, thereby obtaining the excitation-response pair required for the PUF technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 A module block diagram of a piezoresistive sensor provided in one embodiment of the present application;

[0033] Figure 2 A circuit diagram showing a power supply module of a piezoresistive sensor according to the above embodiment of the present application supplies power to a pressure simulation structure;

[0034] Figure 3 A circuit diagram showing a power module of a piezoresistive sensor according to the above embodiment of the present application supplying power to a piezoresistive sensor structure is shown;

[0035] Figure 4 A schematic structural diagram of a piezoresistive sensor structure in a piezoresistive sensor according to the above embodiment of the present application is shown;

[0036] Figure 5 A circuit schematic diagram of a Wheatstone bridge structure in a piezoresistive sensor according to the above embodiment of the present application is shown.

[0037] Figure numerals: 1, piezoresistive sensor; 10, power module; 20, processor; 30, storage module; 40, interface module; 50, piezoresistive sensor structure; 51, pressure simulation structure; 52, Wheatstone bridge; S1, first switch module; S2, second switch module; S3, third switch module; S4, fourth switch module; S5, fifth switch module; S6, sixth switch module; U1, analog voltage; U2, output voltage; U3, driving voltage. DETAILED DESCRIPTION

[0038] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0039] As described in the background technology, the prior art lacks PUF applications for small devices such as MEMS sensors. The inventors have studied that the reason is that small devices such as MEMS sensors lack PUF characteristic values ​​that can be used to generate PUF keys in PUF key applications, that is, corresponding excitation-response pairs (CRPs). Based on this, the inventors found that for the MEMS piezoresistive sensor 1, when the driving voltage U3 changes, the resistance-pressure coefficient of the MEMS piezoresistive sensor 1 will also change accordingly, and for the same piezoresistive sensor 1, this change characteristic is unique. Therefore, the driving voltage U3 can be used as an excitation and the resistance-pressure coefficient can be used as a response, that is, the resistance-pressure coefficient under different driving voltages U3 can be used as the PUF characteristic value of the MEMS piezoresistive sensor 1.

[0040] For details, please refer to the attached Figure 1 and attached Figure 5 An embodiment of the present application provides a piezoresistive sensor 1, comprising: a power module 10, a processor 20, a storage module 30, an interface module 40, and a piezoresistive sensor structure 50.

[0041] More specifically, the power module 10 is used to provide power for the processor 20, the storage module 30, the interface module 40, and the piezoresistive sensor structure 50; the processor 20 is electrically connected to the Wheatstone bridge 52 structure, and is used to calculate the resistance value of the piezoresistive sensor structure 50, and is used to control the working state of the power module 10, and the processor 20 is also used to control the voltage value of the driving voltage U3 output by the power module 10 to the piezoresistive sensor structure 50 in response to the test signal of the external test equipment; the piezoresistive sensor structure 50 includes a pressure simulation structure 51 and a Wheatstone bridge 52, and the pressure simulation structure 51 is used to simulate the change of the external pressure to which the piezoresistive sensor structure 50 is subjected;

[0042] Among them, when the piezoresistive sensor 1 is in the testing state, the power module 10 is electrically connected to the pressure simulation structure 51 of the piezoresistive sensor structure 50, and when the piezoresistive sensor 1 is in the working state, the power module 10 is disconnected from the pressure simulation structure 51 of the piezoresistive sensor structure 50.

[0043] It should be noted that the processor 20, the storage module 30, the interface module 40, and the piezoresistive sensor structure 50 are powered by the power module 10, and the processor 20 is used to switch between the test state and the working state. In the working state, the processor 20 controls the power module 10 to disconnect from the pressure simulation structure 51 of the piezoresistive sensor structure 50 so that the piezoresistive sensor 1 works normally. In the test state, the processor 20 controls the power module 10 to be electrically connected to the pressure simulation structure 51 of the piezoresistive sensor structure 50, and the processor 20 also controls the voltage value of the driving voltage U3 output by the power module 10 to the piezoresistive sensor structure 50 in response to the test signal of the external testing equipment, and according to the piezoresistive sensor structure 50 based on the different simulation voltages U1 applied to the pressure simulation structure 51, the size of the external pressure on the piezoresistive sensor structure 50 can be simulated, and by adjusting the driving voltage U3 of the piezoresistive sensor structure 50, the processor 20 calculates the resistance value of the piezoresistive sensor structure 50, thereby obtaining the excitation-response pair required for the PUF technology.

[0044] In particular, the piezoresistive sensor 1 is provided with a test interface designed exclusively for a test device. When the test device is connected to the test interface, the piezoresistive sensor 1 directly enters the test mode by default, and the power module 10 supplies power to the pressure simulation electrode.

[0045] In other embodiments of the present application, a test switch is provided on the piezoresistive sensor 1. When the test equipment is connected, the test switch is turned on, and the power module 10 supplies power to the pressure simulation electrode;

[0046] In another embodiment of the present application, when the test device is connected, the test device inputs a test instruction to the processor 20 of the sensor, and then the processor 20 controls the power module 10 to supply power to the pressure simulation electrode.

[0047] It is worth noting that the piezoresistive sensor structure 50 includes but is not limited to a MEMS piezoresistive sensor structure 50 or a NEMS piezoresistive sensor structure 50 . This embodiment only takes the structure of the MEMS piezoresistive sensor structure 50 as an example for description.

[0048] In other embodiments of the present application, Figure 4 As shown, the pressure simulation structure 51 includes: a first pressure simulation electrode disposed at the diaphragm end of the cavity structure of the piezoresistive sensor structure 50;

[0049] A second pressure simulation electrode is disposed at a fixed end of the cavity structure of the piezoresistive sensor structure 50 .

[0050] It should be noted that, due to the attraction between the two energized plates due to the electrostatic effect, the voltage difference between the first pressure simulation electrode and the second pressure simulation electrode can be adjusted to simulate the application of different pressures to the piezoresistive sensor structure 50, and by adjusting the driving voltage U3 of the piezoresistive sensor structure 50, it can be used to generate the excitation-response pair required for the PUF technology, and then the PUF key technology can be implemented on the piezoresistive sensor 1. Compared with the solution of directly applying pressure to the piezoresistive sensor structure 50, this solution applies different voltages on the surface of the cavity through the first pressure simulation electrode and the second pressure simulation electrode to simulate the application of different pressures to the piezoresistive sensor structure 50. Compared with the solution of applying pressure, the solution of applying voltage is easier to quantify and easier to reproduce.

[0051] In particular, according to Coulomb's law, like charges repel each other, and unlike charges attract each other. When two objects with the same charge approach each other, a repulsive force is generated between them; and when objects with opposite charges approach each other, an attractive force is generated. The magnitude of this force is proportional to the amount of charge and inversely proportional to the square of the distance, so the greater the voltage between the first pressure simulation electrode and the second pressure simulation electrode, the greater the attraction between the first pressure simulation electrode and the second pressure simulation electrode. Then, the attraction is converted into mechanical deformation with the help of the sensitive film in the piezoresistive sensor structure 50, and then the resistance value of the piezoresistive sensor structure 50 is changed through the piezoresistive effect.

[0052] In particular, the piezoresistive effect refers to the phenomenon that in certain materials, when mechanical stress is applied, the resistivity changes. This effect is due to the stress causing the crystal structure inside the material to change, thereby affecting the mobility and concentration of carriers. The piezoresistive effect is particularly significant in semiconductor materials. When an external force acts on a semiconductor, it causes the lattice to deform, thereby changing the scattering process of carriers, causing the resistivity of the material to change. This change can be used to make a piezoresistive sensor 1 for measuring pressure, stress or other mechanical quantities.

[0053] In particular, the shape of the sensitive film, that is, the diaphragm of the piezoresistive sensor structure 50, includes but is not limited to a circular, rectangular, annular, and porous structure.

[0054] In other embodiments of the present application, the processor 20 is used to control the connection and disconnection of the power module 10 and the first pressure simulation electrode and the second pressure simulation electrode in response to a first test signal from an external testing device, and to control the potential and / or current applied by the power module 10 to the first pressure simulation electrode and the second pressure simulation electrode.

[0055] It should be noted that the processor 20 can be used for precise control to ensure that the potential and / or current applied during the test is accurate and stable, thereby improving the accuracy and reliability of the test results; and the processor 20 can also automatically respond to signals from external testing equipment to realize an automated testing process and improve the efficiency of the entire testing process.

[0056] In other embodiments of the present application, the power supply module 10 includes a battery, a first switch module S1, and a first voltage adjustment module. The first voltage adjustment module is electrically connected to the battery through the first switch module S1. The first switch module S1 responds to the first test signal sent by the processor 20 to turn on or off the connection between the first voltage adjustment module and the battery. The first voltage adjustment module responds to the first voltage signal sent by the processor 20 to adjust the potential and / or current output to the first pressure simulation electrode and the second pressure simulation electrode.

[0057] In other embodiments of the present application, the first test signal and the first voltage signal are the same signal.

[0058] In particular, the voltage output by the battery is the output voltage U2.

[0059] It should be noted that after receiving the first voltage signal sent by the processor 20, the first voltage adjustment module adjusts the potential and / or current applied to the first pressure simulation electrode and the second pressure simulation electrode, thereby simulating the magnitude of the external pressure applied to the piezoresistive sensor structure 50, laying the foundation for the subsequent processor 20 to calculate the resistance value of the piezoresistive sensor structure 50.

[0060] In other embodiments of the present application, Figure 2 As shown, the first voltage adjustment module includes k first voltage output nodes, and a first resistor R1, a first resistor R2, ... a first resistor Rk connected in series in sequence, k is a positive integer, a first voltage output node is provided between two adjacent first resistors, and the first switch module S1 is a k-to-2 selector;

[0061] One end of the battery is connected to the first pressure simulation electrode, and the other end is connected to the input end of the first resistor R1. The input end of the first resistor R1 is the first first voltage output node. The input end of the k-to-2 selector is connected to the k first voltage output nodes through k second switch modules S2, and the output end of the k-to-2 selector is connected to the second pressure simulation electrode. The k-to-2 selector is used to respond to the first voltage signal of the processor 20 and select the first voltage output node that is turned on.

[0062] It should be noted that, when it is necessary to apply different voltages to the pressure simulation structure 51 of the piezoresistive sensor structure 50, the voltage division principle can be used to connect different numbers of resistors according to different needs, so that the voltages on different numbers of resistors are applied to the pressure simulation structure 51 of the piezoresistive sensor structure 50, thereby meeting the need to apply different voltages to the pressure simulation structure 51 of the piezoresistive sensor structure 50. Compared with the solution using a sliding rheostat, this solution can automatically adjust the voltage output of the pressure simulation structure 51 applied to the piezoresistive sensor structure 50 by means of hardware or software, which can reduce labor costs and improve test efficiency.

[0063] In other embodiments of the present application, the power supply module 10 also includes a third switch module S3 and a second voltage adjustment module. The second voltage adjustment module is electrically connected to the battery through the third switch module S3. The third switch module S3 responds to the second test signal sent by the processor 20 to turn on or off the connection between the second voltage adjustment module and the battery. The second voltage adjustment module responds to the second voltage signal sent by the processor 20 to adjust the voltage output to the piezoresistive sensor structure 50.

[0064] It should be noted that the processor 20 can be used to control the second voltage adjustment module and the third switch module S3, so as to adjust the driving voltage U3 output to the piezoresistive sensor structure 50, that is, adjust the voltage value of the electric energy supplied to the piezoresistive sensor structure 50.

[0065] In other embodiments of the present application, Figure 3 As shown, the second voltage adjustment module includes n second voltage output nodes, and a second resistor R1, a second resistor R2, ... a second resistor Rn connected in series in sequence, n is a positive integer, and a second voltage output node is provided between two adjacent second resistors, and the third switch module S3 is an n-to-2 selector;

[0066] One end of the battery is connected to the first input end of the driving voltage U3 of the piezoresistive sensor structure 50, and the other end is connected to the input end of the second resistor R1. The input end of the second resistor R1 is the first second voltage output node. The input end of the n-to-2 selector is connected to the n second voltage output nodes through n fourth switch modules S4. The output end of the n-to-2 selector is connected to the second input end of the driving voltage U3 of the piezoresistive sensor structure 50. The n-to-2 selector is used to respond to the second voltage signal of the processor 20 and select the second voltage output node to be turned on.

[0067] It should be noted that, when it is necessary to apply different voltages to the piezoresistive sensor structure 50, the voltage division principle can be used to connect different numbers of resistors according to different needs, so that the voltages on different numbers of resistors can be applied to the piezoresistive sensor structure 50, thereby meeting the needs of applying different voltages to the piezoresistive sensor structure 50. Compared with the solution using a sliding rheostat, this solution can automatically adjust the voltage output applied to the piezoresistive sensor structure 50 at the hardware or software level, which can reduce labor costs and improve test efficiency.

[0068] In other embodiments of the present application, the power supply module 10 also includes a fifth switch module S5 and a sixth switch module S6, wherein the first end of the sixth switch module S6 is connected to the positive electrode V+ of the output voltage U2 of the piezoresistive sensor structure 50, and the second end is grounded; the first end of the fifth switch module S5 is connected to the negative electrode V- of the output voltage U2 of the piezoresistive sensor structure 50, and the second end is grounded; the sixth switch module S6 is closed in response to the bridge output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the fifth switch is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

[0069] In particular, the output voltage of the Wheatstone bridge is the bridge output voltage Vout.

[0070] It should be noted that the fifth switch module S5 can be closed or closed in response to the output voltage test signal of V- or V+, and the sixth switch module S6 can be closed or closed in response to the test signal of V- or V+, so as to accurately measure the voltage applied to the piezoresistive sensor structure 50 at a certain moment. Compared with directly measuring the voltage output to the piezoresistive sensor structure 50, this solution can effectively eliminate the system errors caused by power supply voltage fluctuations, resistance temperature coefficient, etc., improve the measurement accuracy, and can effectively reduce the influence of external electromagnetic interference on the measurement results, so as to improve the accuracy of the measurement of the voltage applied to the piezoresistive sensor structure 50 at a certain moment.

[0071] In particular, the piezoresistive sensor 1 includes but is not limited to a MEMS / NEMS pressure sensor, a MEMS / NEMS force sensor, a MEMS / NEMS acceleration sensor, a MEMS / NEMS displacement sensor, a MEMS / NEMS strain sensor, a MEMS / NEMS flow sensor, or a MEMS / NEMS torque sensor.

[0072] In particular, when the piezoresistive sensor 1 is a wireless sensor, the piezoresistive sensor 1 further includes an antenna module and a communication module, and the antenna module and the communication module are used to establish wireless communication with an external test terminal or test equipment.

[0073] It is worth noting that other embodiments of the present application also provide a sensor, including a power module 10, a processor 20, a storage module 30, an interface module 40, and a piezoresistive sensor structure 50; the power module 10 is used to provide power to the processor 20, the storage module 30, the interface module 40, and the piezoresistive sensor structure 50; the processor 20 is electrically connected to the Wheatstone bridge 52 structure of the piezoresistive sensor structure 50, and is used to calculate the resistance value of the piezoresistive sensor structure 50, and is used to control the working state of the power module 10, and the processor 20 is also used to respond to the test of the external test equipment signal, controlling the voltage value of the driving voltage U3 output by the power module 10 to the piezoresistive sensor structure 50; the power module 10 comprises a battery, a third switch module S3, and a second voltage adjustment module, the second voltage adjustment module is electrically connected to the battery through the third switch module S3, the third switch module S3 responds to the second test signal sent by the processor 20, turns on or off the connection between the second voltage adjustment module and the battery, and the second voltage adjustment module responds to the second voltage signal sent by the processor 20, adjusts the voltage value output to the piezoresistive sensor structure 50;

[0074] Among them, when the sensor is in a testing state, the third switch module S3 turns on the connection between the second voltage adjustment module and the battery, and when the sensor is in a working state, the third switch module S3 disconnects the connection between the second voltage adjustment module and the battery, and the battery directly powers the piezoresistive sensor structure 50.

[0075] It should be noted that the sensor applies a driving voltage U3 with different voltage values ​​adjusted to the piezoresistive sensor structure 50 and calculates the resistance value of the piezoresistive sensor structure 50 with the help of the processor 20, thereby obtaining the excitation-response pair required by the PUF technology.

[0076] In particular, other embodiments of the present application further provide a method for generating a PUF characteristic value based on the piezoresistive sensor 1, comprising the following steps:

[0077] Step A: providing a piezoresistive sensor 1, and turning on the power supply of the piezoresistive sensor 1, wherein the piezoresistive sensor 1 comprises a power supply, a driving voltage U3 adjustment circuit, and a piezoresistive sensor structure 50; the driving voltage U3 adjustment circuit is used to adjust the driving voltage U3 input to the piezoresistive sensor 1; the piezoresistive sensor structure 50 comprises a pressure simulation structure 51 and a Wheatstone bridge 52, and the pressure simulation structure 51 is used to simulate the change of the external pressure to which the piezoresistive sensor 1 is subjected;

[0078] Step B: inputting the driving voltage U3 to the piezoresistive sensor 1 through the driving voltage U3 adjustment circuit;

[0079] Step C1: Under the driving voltage U3, the pressure simulation structure 51 simulates the M1 group of external pressure groups, obtains the resistance-pressure coefficient K of the piezoresistive sensor 1 under each group of external pressure, and obtains the M1 group of resistance-pressure coefficient K, each group of external pressure groups includes 2 different pressure values, and the resistance under each group of external pressure is 2;

[0080] Step C2: measuring an initial output voltage U2 of the piezoresistive sensor 1 under the driving voltage U3, wherein the initial output voltage U2 is the output voltage U2 when the external pressure additionally applied to the piezoresistive sensor 1 is zero;

[0081] Step D: adjusting the driving voltage U3, repeating steps B-C1, until a plurality of resistance-pressure coefficients K under N sets of driving voltage U3 are obtained, the number of K being M1+M2+......+Mn, wherein N and M1-Mn are both positive integers;

[0082] Step E: using the N groups of driving voltages U3 as excitations and multiple K values ​​under each driving voltage U3 as responses to generate PUF characteristic values.

[0083] The above-mentioned PUF characteristic value generation method based on the piezoresistive sensor 1 utilizes the fact that the resistance-pressure coefficient K of the piezoresistive sensor 1 under different driving voltages U3 is also different, but K has a unique and stable characteristic under different driving voltages U3. The driving voltage U3 in the piezoresistive sensor 1 is used as excitation, and the resistance-pressure coefficient under different pressures is used as response to generate the PUF characteristic value of the sensor. There is no need to increase additional design and production costs, thereby reducing the PUF cost.

[0084] In particular, the values ​​of M1, M2, ..., Mn may be the same or different.

[0085] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor 20 involved in each embodiment provided in this application may be a general-purpose processor 20, a central processing unit 20, a graphics processor 20, a digital signal processor 20, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0086] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0087] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A piezoresistive sensor, characterized in that: include: A power module, a processor, a storage module, an interface module, and a piezoresistive sensor structure; the power module is used to provide power to the processor, the storage module, the interface module, and the piezoresistive sensor structure; the processor is electrically connected to the Wheatstone bridge structure, and is used to calculate the resistance value of the piezoresistive sensor structure, and is used to control the working state of the power module, and the processor is also used to control the voltage value of the driving voltage output by the power module to the piezoresistive sensor structure in response to a test signal of an external test device; the piezoresistive sensor structure includes a pressure simulation structure and a Wheatstone bridge, and the pressure simulation structure is used to simulate the change of the external pressure on the piezoresistive sensor structure; Among them, when the piezoresistive sensor is in a testing state, the power module is electrically connected to the pressure simulation structure of the piezoresistive sensor structure, and when the piezoresistive sensor is in a working state, the power module is disconnected from the pressure simulation structure of the piezoresistive sensor structure.

2. The piezoresistive sensor according to claim 1, characterized in that: The pressure simulation structure comprises: a first pressure simulation electrode disposed at a diaphragm end of a cavity structure of the piezoresistive sensor structure; A second pressure simulation electrode is disposed at a fixed end of the cavity structure of the piezoresistive sensor structure.

3. The piezoresistive sensor according to claim 2, characterized in that: The processor is used to control the connection and disconnection between the power module and the first pressure simulation electrode and the second pressure simulation electrode in response to a first test signal from an external testing device, and to control the potential and / or current applied by the power module to the first pressure simulation electrode and the second pressure simulation electrode.

4. The piezoresistive sensor according to claim 3, characterized in that: The power supply module includes a battery, a first switch module, and a first voltage adjustment module. The first voltage adjustment module is electrically connected to the battery through the first switch module. The first switch module responds to a first test signal sent by the processor to turn on or off the connection between the first voltage adjustment module and the battery. The first voltage adjustment module responds to a first voltage signal sent by the processor to adjust the potential and / or current output to the first pressure simulation electrode and the second pressure simulation electrode.

5. The piezoresistive sensor according to claim 4, characterized in that: The first voltage adjustment module includes k first voltage output nodes, and first resistors R1, R2 to Rk connected in series in sequence, k is a positive integer, a first voltage output node is provided between two adjacent first resistors, and the first switch module is a k-to-2 selector; One end of the battery is connected to the first pressure simulation electrode, and the other end is connected to the input end of the first resistor R1. The input end of the first resistor R1 is the first voltage output node 1. The input end of the k-to-2 selector is connected to the k first voltage output nodes through k second switch modules, and the output end of the k-to-2 selector is connected to the second pressure simulation electrode. The k-to-2 selector is used to respond to the first voltage signal of the processor and select the first voltage output node to be turned on.

6. The piezoresistive sensor according to claim 4, characterized in that: The power supply module also includes a third switch module and a second voltage adjustment module. The second voltage adjustment module is electrically connected to the battery through the third switch module. The third switch module responds to a second test signal sent by the processor to turn on or off the connection between the second voltage adjustment module and the battery. The second voltage adjustment module responds to a second voltage signal sent by the processor to adjust the voltage value output to the piezoresistive sensor structure.

7. The piezoresistive sensor according to claim 6, characterized in that: The second voltage adjustment module includes n second voltage output nodes, and second resistors R1, R2 to Rn connected in series in sequence, where n is a positive integer, and a second voltage output node is provided between two adjacent second resistors, and the third switch module is an n-to-2 selector; One end of the battery is connected to the first input end of the driving voltage of the piezoresistive sensor structure, and the other end is connected to the input end of the second resistor R1, the input end of the second resistor R1 is the second voltage output node 1, the input end of the n-to-2 selector is connected to the n second voltage output nodes through n fourth switch modules, the output end of the n-to-2 selector is connected to the second input end of the driving voltage of the piezoresistive sensor structure, and the n-to-2 selector is used to respond to the second voltage signal of the processor and select the second voltage output node to be turned on.

8. The piezoresistive sensor according to claim 1, characterized in that: The power supply module also includes a fifth switch module and a sixth switch module, wherein the first end of the sixth switch module is connected to the positive electrode V+ of the output voltage of the piezoresistive sensor structure, and the second end is grounded; the first end of the fifth switch module is connected to the negative electrode V- of the output voltage of the piezoresistive sensor structure, and the second end is grounded; the sixth switch module is closed in response to the output voltage test signal of V-, and is opened in response to the output voltage test signal of V+; the fifth switch is closed in response to the output voltage test signal of V+, and is opened in response to the output voltage test signal of V-.

9. The piezoresistive sensor according to any one of claims 1 to 8, characterized in that: The piezoresistive sensor is a MEMS / NEMS pressure sensor, a MEMS / NEMS force sensor, a MEMS / NEMS acceleration sensor, a MEMS / NEMS displacement sensor, a MEMS / NEMS strain sensor, a MEMS / NEMS flow sensor, or a MEMS / NEMS torque sensor.

10. A sensor, characterized in that: The invention comprises a power module, a processor, a storage module, an interface module, and a piezoresistive sensor structure; the power module is used to provide power for the processor, the storage module, the interface module, and the piezoresistive sensor structure; the processor is electrically connected to the Wheatstone bridge structure of the piezoresistive sensor structure, and is used to calculate the resistance value of the piezoresistive sensor structure and to control the working state of the power module; the processor is also used to control the voltage value of the driving voltage output by the power module to the piezoresistive sensor structure in response to a test signal of an external test device; the power module comprises a battery, a third switch module, and a second voltage adjustment module; the second voltage adjustment module is electrically connected to the battery through the third switch module; the third switch module switches on or off the connection between the second voltage adjustment module and the battery in response to a second test signal sent by the processor; the second voltage adjustment module adjusts the voltage value output to the piezoresistive sensor structure in response to a second voltage signal sent by the processor; Among them, when the sensor is in a testing state, the third switch module turns on the connection between the second voltage adjustment module and the battery, and when the sensor is in a working state, the third switch module disconnects the connection between the second voltage adjustment module and the battery, and the battery directly powers the piezoresistive sensor structure.

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