61 results about "Piezoresistive effect" patented technology

The invention discloses a PT symmetrical hot-pressing resistance MEMS wind speed and wind direction sensor. The sensor comprises four groups of PT symmetrical MEMS resonators which are orthogonally distributed and have hot-pressing resistance feedback; the PT symmetrical MEMS resonator comprises two cantilever beam resonators with completely same structures, a coupling spring beam connected with the two resonators, and a constant current source connected with one resonator, each cantilever resonator comprises two anchor areas, a wide beam connected with the anchor areas, a narrow beam with a piezoresistive effect, a warped thin plate structure and external electrodes located on the two sides of the thin plate structure. Wind speed and wind direction signals are converted into rigidity change of the resonator array through mechanical action by means of a warped thin plate structure, and the rigidity change enables the PT symmetrical MEMS system to deviate from an EP point, so that system frequency splitting is caused. As the frequency splitting quantity of the PT symmetric system is in direct proportion to the square root of the disturbance quantity, the wind speed and direction sensor can detect tiny wind speed signals, and has the advantages of very high sensitivity, simple process, high integration level and the like.

The invention relates to the technical field of underground energy storage, in particular to a gas storage cavern grouting confining pressure real-time monitoring system and method based on the piezoresistive effect, and the system comprises a grouting reinforcement module which is used for injecting grout into a target gas storage cavern and laying a lining to form a grouting reinforcement area; the resistance detection module is used for detecting resistivity distribution characteristics of the grouting reinforcement area in real time; the confining pressure monitoring module is used for analyzing the resistivity distribution characteristics based on a preset piezoresistive modified slurry resistivity-surrounding rock stress relation model to obtain the actual stress state of surrounding rock; and the early warning regulation and control module is used for triggering an early warning signal based on the actual stress state of the surrounding rock and releasing gas. According to the invention, continuous and non-contact measurement of the surrounding rock stress state of the gas storage cavern can be realized.

The invention provides a composite sensing skin material suitable for an automobile collision dummy. The composite sensing skin material comprises the following components: a dummy skin material, graphene and a gallium-indium alloy. By adding the graphene and the gallium-indium alloy, the resistance value of the dummy skin material is greatly reduced, and the composite sensing skin material has a piezoresistive effect. When the material is prepared into a dummy, in the process of automobile collision performance testing, effective detection of dummy damage is achieved through the piezoresistive effect, and more reliable data support is provided for automobile safety assessment.

The invention discloses a thermocompression resistance PT symmetrical MEMS pressure sensor, which comprises two resonators with identical structures, and the two resonators are connected through a group of coupling spring beams. Each resonator comprises four anchor areas connected with the thin film substrate, narrow beams which are connected with the four anchor areas and have a piezoresistive effect, and a mass block connected with the four narrow beams, and the four anchor areas are symmetrically distributed on the two sides of the mass block. For one of the resonators, a current path is formed through connection of a constant current source in the anchor section on the same side of the mass block. Under the action of a constant current source, hot resistance pressing feedback is generated at narrow beams of the resonators, so that the two coupled resonators form a PT symmetric system, and the PT symmetric resonators are initially arranged at an Exception Point (EP) point. When pressure acts on the lower surface of the substrate, the substrate generates strain, the position of the anchor area is driven to change, the rigidity of the resonator is changed, a PT symmetric system deviates from an EP point, the system eigenfrequency is split and shows pull-ratio oscillation, and the frequency splitting amount depends on the pressure borne by the substrate. Because the EP point has a large response to tiny disturbance, the thermal pressure resistance PT symmetric MEMS pressure sensor can realize accurate measurement of weak pressure change, and has the advantages of high sensitivity and simple manufacturing process.

The invention discloses a common-film differential high-static-pressure resonant differential pressure sensor based on hot resistance driving, and relates to a pressure sensor. The invention provides a novel sensor structure based on a thermal piezoresistive effect. The sensor adopts a thermal piezoresistive effect for driving and piezoresistive detection, and comprises a low-voltage side pressure sensing film, a bonding oxide layer, a structural layer, a buried oxide layer, a high-voltage side pressure film and a substrate layer, the low-voltage side pressure sensing film is made of a silicon material, the structural layer and the high-voltage side pressure film are made of SOI sheets, and the substrate layer is made of BF33 glass; the high-pressure side pressure film and the low-pressure side pressure film respectively sense high pressure and low pressure and sense a difference value between the high pressure and the low pressure through deformation of the pressure films, deflection deformation of the films generates tensile stress in a central area and pressure stress in an edge area, the double resonators sense opposite stress and generate opposite frequency deviation, and the difference between the two is used for representing a differential pressure value. The glass substrate is mainly used for isolating thermal stress of the packaging stainless steel base.

The invention discloses a flexible multi-dimensional force sensing device, comprising a first insulator having a plurality of three-dimensional structures protruding from the surface; the first conductor is made of a flexible conductive material and is in the shape of long-strip stitches, the stitches are connected with one another to form a conductive network, the stitches are adhered to the surface of the first insulator and distributed on the surface of the three-dimensional structure unit, and the three-dimensional structure unit is used for transmitting borne normal pressure, shear force and torsional force to the corresponding stitches; the first conductor has a piezoresistive effect, when the first conductor is stressed to generate elastic deformation, the stitch is stretched or compressed, and the resistance at the stressed position changes regularly; and connecting each trace of the first conductor to an external electrical impedance scanning imaging device so as to detect pressure information of each position on the surface of the flexible multi-dimensional force sensing device at each moment. On the basis, the flexible multi-dimensional force sensing equipment is simple in structure, low in cost, easy to process, good in fitting degree for a curved surface shape, and excellent in stability and robustness.

The invention discloses a self-calibration flexible pressure sensing device, which comprises a first conductor and a second conductor which are in a strip-shaped, strip-shaped or linear structure and both have a piezoresistive effect. The isolating layer is arranged between the first conductor and the second conductor, and through holes or long grooves with continuous through holes are distributed in the surface of the isolating layer; and an encapsulation layer covering the first conductor and the second conductor. According to the embodiment of the invention, a dual-core layer piezoresistive structure and a through hole type isolation layer design are adopted, the dual-core layer design covers a range from small pressure to large pressure, the range limitation of a single material is broken through, and a dynamic self-calibration technology is combined, so that multi-parameter integrated detection of pressure magnitude, position and width is realized; the sensor array has the advantages of self-adaption to environment change, wide-range detection, multi-scene applicability and the like, the sensor for realizing the functions only needs four wires, complex wiring of the sensor array is avoided, miniaturization and flexibility are facilitated, a narrow strip-shaped flexible structure is adopted as a whole, and flexible arrangement of sensor tracks and garment integration are facilitated.

The present invention discloses a high-sensitivity micro-mechanical system (MEMS) differential pressure sensor and a preparation method thereof, wherein the differential pressure sensor comprises a silicon nitride (SiN) with an etched window. x ) thin films, silicon (Si) substrates, SiN x Suspended structure self-supporting film, PdSe2 polycrystalline ultra-thin film, metal electrode and surface passivation layer. Ultra-thin PdSe2 has significant piezoresistive effect and ultra-thin suspended SiN x The device has a high pressure differential stress sensing characteristic, and the high Young's modulus SiN x The device ensures the reliability of differential pressure sensing. The Wheatstone bridge formed by the optimized metal electrode structure suppresses temperature drift, ensuring the accuracy of differential pressure measurement. Advantages of this invention include compatibility with silicon-based semiconductor processes, high yield, strong repeatability, good stability, and high device sensitivity.

The invention belongs to the technical field of pipeline repair, and particularly relates to a nano conductive composite material pipeline repair layer health monitoring system and method based on a piezoresistive effect. The invention discloses a nano conductive composite material pipeline repair layer health monitoring system based on a piezoresistive effect. The system comprises a sensing layer, a data acquisition layer, a transmission layer, an analysis layer and an application layer, wherein the sensing layer is a graphene / carbon nanotube hybrid reinforced composite material pipeline repairing layer made of a self-sensing material; the data acquisition layer is used for acquiring signals and carrying out multi-channel acquisition, signal conditioning, A / D conversion and time synchronization; the transmission layer performs data communication through wired transmission / wireless transmission; the analysis layer performs data processing and algorithm processing including data preprocessing, trend analysis, damage identification and a positioning algorithm; and the application layer realizes user interaction and display, and performs visual interface, alarm push, operation and maintenance decision and report generation. The invention provides a nano conductive composite material pipeline repair layer health monitoring system and method based on a piezoresistive effect, and aims to solve the problems of no basis for conductive threshold design, insufficient monitoring sensitivity, incomplete system, indefinite alarm criterion, low positioning precision, low intelligent degree, high cost and the like in the prior art.

The invention belongs to the technical field of bearings, and discloses a foil dynamic pressure radial gas bearing bump foil creep test method, which is characterized in that a miniature rubber block is inserted between a top foil and a rigid substrate, and the miniature rubber block is used as a flexible element, is in direct contact with the top foil, and deforms under the action of a compression load transmitted by the top foil; a monocrystalline silicon semiconductor strain gauge is pasted on the side face of the miniature rubber block, and the direction is perpendicular to the direction of the compression load; in the running process of the bearing, the output strain value of the strain gauge is monitored in real time through a data acquisition system; the semiconductor strain gauge is a sensitive element manufactured based on the piezoresistive effect of semiconductor monocrystalline silicon, the resistivity of a semiconductor crystal material is changed when the semiconductor crystal material is stressed in a certain direction and deforms, and strain, stress and the like are indirectly measured. The device has the beneficial effect that the problem that the creep strain is difficult to test in real time due to the tiny structure of the bump foil is solved.

The invention discloses a pressure measuring device and a measuring method, particularly relates to the technical field of pressure measurement, and solves the technical problem that a pressure measuring device in the prior art is not suitable for teaching. According to the technical scheme, a double-strip-shaped copper foil electrode is fixed to the surface of an acrylic bearing plate, 8B pencil graphite EVA foam covers the double-strip-shaped copper foil electrode to form a sensor, and the tail end of the electrode is connected with a wire to be connected into a Wheatstone bridge; a bridge output signal is sampled by 860SPS through an ADS1115 module, and meanwhile, the NTC thermistor compensates the temperature drift in real time; the sensor receives pressure and then is connected with the Arduino through a wire to convert and output pressure change to a computer for real-time display; according to the invention, students can deeply understand a piezoresistive effect principle through a low-cost self-made device, observe dynamic pressure changes in real time, and explore a pressure distribution rule.

The invention discloses an insole type pressure-shear force sensor for early warning of sole ulcer of a diabetic patient, and belongs to the technical field of electronic skin. The device comprises a pressure sensing layer, a shear force sensing layer and a processing and transmission system, the pressure sensing layer comprises a plurality of pressure sensor units distributed in an array mode, and each pressure sensor unit works based on a piezoresistive effect principle; the shear force sensing layer is positioned above the pressure sensing layer and comprises a plurality of distributed capacitive sensors; the pressure sensing layer and the shearing force sensing layer are electrically connected with the adapter plate respectively so as to summarize pressure data and shearing force data, and then the adapter plate is connected with the processing and transmitting system. The device can accurately measure the pressure and shear force of the foot sole of the diabetic patient in daily activities in real time and feed back data, so that abnormity can be found in time, the occurrence risk of foot sole ulcer can be prevented and reduced, and effective technical support is provided for foot health management of the diabetic patient.

This invention discloses a method and system for online monitoring of fiber pressure bearing during composite material molding, belonging to the field of composite material molding and preparation. The method includes: S1, embedding an online fiber pressure bearing monitoring sensor into the interlayer of the composite material to be monitored; the online fiber pressure bearing monitoring sensor is a porous conductive network thin-film sensor with piezoresistive effect; S2, applying pressure in the thickness direction of the composite material during molding; S3, monitoring the resistance change of the online fiber pressure bearing monitoring sensor to reflect the change in fiber pressure bearing during the composite material molding process. This invention eliminates the influence of resin pressure on the sensor signal output during composite material molding, achieving accurate online monitoring of fiber pressure bearing during the composite material molding process. Furthermore, the monitoring process does not affect the molding process or quality of the composite material, and does not reduce the service performance of the molded composite material, or even improve the interlayer mechanical properties.

The embodiment of the invention discloses wearable knee joint equipment, a knee joint rehabilitation evaluation method and computing equipment. The wearable knee joint equipment comprises a flexible substrate; the sensing unit is integrated on the flexible substrate and comprises an electromyographic sensing module used for collecting surface electromyographic signals of rectus femoris for driving the knee joint to move; the muscular tension sensing module is used for generating a muscular tension signal by detecting skin deformation caused by knee joint movement based on the piezoresistive effect; the joint angle sensing module is used for generating a knee joint motion range signal by detecting knee joint flexion and extension strain based on the piezoresistive effect; the signal processing module is connected with the sensing units and used for processing and wirelessly transmitting the surface electromyogram signals, the muscular tension signals and the knee joint movement signals to a computing device so that the computing device can determine the state evaluation result of the knee joint rehabilitation state based on the signals. The possibility is provided for remote dynamic monitoring of TKA postoperative rehabilitation, and the accuracy of rehabilitation state evaluation is improved.

This utility model discloses a MEMS multidimensional force sensor, relating to the field of sensor technology. It includes a sensor body comprising an upper mounting flange, a lower mounting flange, an elastomer, and strain gauges. The elastomer is mounted between the upper and lower mounting flanges, and the strain gauges are adhered to the surface of the elastomer. The elastomer employs an asymmetric structure, and the strain gauges are flexible MEMS strain gauges capable of converting the deformation of the elastomer into a change in resistance through the piezoresistive effect. This utility model achieves synchronous decoupled measurement of X, Y, and Z forces and Mx, My, and Mz moments by setting four sets of asymmetric strain beams around the central strain table and arranging sixteen sets of flexible MEMS strain gauges in the key stress concentration areas of each crossbeam and longitudinal beam. This effectively reduces interdimensional coupling errors and improves the accuracy of multidimensional force detection.

The present application relates to a kind of sensor for capturing and identifying pressure signal and its preparation and application.The sensor is realized by piezoresistive effect pressure sensing, which is composed of three parts of sensitive layer, electrode, encapsulation layer.Sensitive layer is graphene composite silk fibroin aerogel material, its feature is with ordered three-dimensional porous layered structure, with small density, electrically conductive, compressible-rebound, non-toxic and other characteristics;Electrode is high-conductivity material, and encapsulation layer is flexible scalable polymer material.Benefiting from the excellent piezoresistive change and compression-rebound performance of graphene composite silk fibroin aerogel, the prepared flexible pressure sensor can not only quickly detect pressure and deformation, but also has excellent flexibility and durability.In addition, the preparation method of the sensor is simple, raw material is green and environmentally friendly, detection range is wide, and sensitivity linearity is high.Therefore, the sensor has the potential of large-scale manufacturing, and has broad application prospects in the field of flexible wearable electronic equipment.

The application provides a slope piezoelectric intelligent pavement weighing characterization method based on a multi-axle heavy vehicle. The method first selects a to-be-detected pavement, and arranges a piezoelectric sensor array on the cross section of the to-be-detected pavement to form an intelligent pavement. When the vehicle passes through the intelligent pavement, the piezoresistive effect of the piezoelectric sensor converts the mechanical strain into an electric charge signal output. Then, a corresponding voltage signal is generated through a charge-voltage converter, and the relationship between the voltage and the pressure is established in combination with the sensitivity information on the piezoelectric sensor. Based on the pressure distribution data, the position of each wheel of the vehicle is determined. The vehicle speed is calculated in combination with the time interval and the position data of the wheel. Based on the pressure data and the wheel position information, the relationship between the pressure and the load is established, and then the weight applied by each wheel is calculated. The application can significantly improve the weighing accuracy under the condition of a slope pavement, and provides a more reliable and efficient solution for the weighing problem of the multi-axle heavy vehicle.

The invention discloses a shale proppant embedding damage in-situ real-time monitoring system and a shale proppant embedding damage in-situ real-time monitoring method, a self-sensing shale sample assembly with an innovative structure is adopted, and a conductive sensing layer in the self-sensing shale sample assembly is extremely high in electric signal response speed based on a piezoresistive effect; in the load test process, the whole process dynamic state of embedding, compacting and crushing the upper shale sample and the lower shale sample by the proppant is completely recorded, and in-situ real-time monitoring data is obtained; the conductive induction layers are made of specific materials and are coated on the stress surfaces of the upper shale sample and the lower shale sample and the non-stress surfaces of the side walls of the upper shale sample and the lower shale sample, the conductive induction layers with lateral extension structures are formed after the conductive induction layers are cured, and lateral electrode sensors are installed on the side walls of the two samples respectively. According to the structure, the lateral electrode sensor is prevented from being directly damaged by vertical high-pressure load, sensitive capture of the dynamic embedding process of the proppant is ensured, and finally the embedding depth of the proppant is calculated in real time according to monitoring data, so that the embedding damage condition of the proppant is accurately determined in real time.

The present invention provides a strain-type piezoresistive effect sensitive element and a manufacturing method thereof, wherein the sensitive element includes an SOI wafer, a resistor, a second insulating layer and a second shielding layer, the SOI wafer includes a first shielding layer and a first insulating layer, the resistor is arranged on a side of the first insulating layer away from the first shielding layer, the second insulating layer is arranged on a side of the first insulating layer away from the first shielding layer and covers the resistor, and the second shielding layer covers the outer side of the second insulating layer and is located on a side of the resistor away from the first shielding layer; wherein, at least one of the first shielding layer and the second shielding layer is also surrounded by the circumferential outer side of the resistor, so that the resistor is surrounded by the first shielding layer and the second shielding layer on the upper and lower sides and the circumferential outer side, thereby improving the shielding effect of the strain-type piezoresistive effect sensitive element on the external electromagnetic field, avoiding the influence of the external electromagnetic field, and thus improving the strain accuracy of the detected object and the measurement stability.

The invention discloses a pressure sensor based on a non-metal suspended structure-two-dimensional material-metal mixed structure, and the pressure sensor comprises a substrate structure which comprises a solid material substrate and a non-metal suspended structure located on the solid material substrate, and a cavity formed through etching is formed below the non-metal suspended structure; the pressure-sensitive layer is positioned on the non-metal suspended structure, is made of a single-layer or multi-layer conductive two-dimensional material and forms a pressure sensing functional area; the electrode layer is located on the pressure-sensitive layer, comprises at least two metal electrodes and is used for being connected with an external circuit and conducting electrical signals. The invention also discloses a preparation method and application of the pressure sensor. According to the invention, the excellent piezoresistive effect of the two-dimensional material is fully utilized, high-sensitivity pressure detection is realized on a planar microstructure, the size is small, the integration degree is high, and the application coverage is wide.

The invention discloses a diamond piezoresistive effect pressure sensitive structure design method, which comprises the following steps of: forming a buried oxide layer through ion implantation by taking a single crystal diamond as a substrate, and processing a three-dimensional gradient cantilever beam array and a hyperboloid diaphragm initial contour on the diamond substrate by utilizing an oxygen plasma anisotropic etching technology; and then, carrying out crystal orientation selective etching by adopting Ar / Cl2 mixed gas to form a V-shaped stress concentration groove. And finally, through an atomic layer deposition technology, an Al2O3 / TiN composite transition layer is deposited on the surface of the double-curved-surface diaphragm, and gradient distribution of carrier mobility is regulated and controlled, so that synergistic enhancement of a piezoresistive effect and structural mechanics is realized. The structure is high in sensitivity, high in stability, excellent in corrosion resistance and abrasion resistance, good in heat dissipation performance and suitable for high-precision pressure measurement scenes.

The application discloses a kind of robot tactile perception and force error compensation systems for circuit breaker operation and maintenance, it is related to power equipment operation and maintenance automation technical field, including tactile perception module, using piezoresistive effect flexible sensor array, support 16-way data synchronous acquisition;Force error compensation module, integrated impedance control algorithm and multi-source error compensation model;System control module, using industrial grade embedded controller, support CAN bus and Ethernet communication;Environment adaptation module, deployment temperature and humidity and vibration sensor, dynamic adjustment parameter;Execution drive module, contain servo driver and adaptive clamping mechanism;Data storage and analysis module, using edge-cloud architecture;Safety protection module, with over force protection and insulation monitoring function.The application improves tactile perception precision and force error compensation effect, enhances complex environment adaptation capability;Through self-calibration and data optimization, keep long-term stable operation, adapt to different specifications circuit breaker operation and maintenance demand.

A broadband graphene array type transceiving integrated flexible transducer for bionic underwater communication belongs to the technical field of broadband underwater acoustic transducers and comprises a plurality of transceiving integrated transduction array units with graphene composite materials as core functional layers. The array unit comprises a graphene composite material core function layer, conductive metal film layers located on the upper surface and the lower surface of the graphene composite material core function layer, an elastic substrate layer located on the upper portion and a waterproof protection layer. The graphene composite material core function layer emits broadband underwater acoustic signals based on the thermo-acoustic effect and receives the underwater acoustic signals based on the piezoresistive effect. And the conductive metal film layer is connected with other transduction array units through flexible insulated wires for electric signal transmission. According to the invention, each array unit has the functions of underwater acoustic signal transmitting and receiving at the same time, and the structure is simple; the composite material has excellent flexibility, excellent hyperelasticity and excellent mechanical strength, and provides a device breakthrough for the fields of bionic marine environment monitoring, underwater operation monitoring and the like.

This invention provides a method and device for monitoring roadbed moisture content based on the piezoresistive effect. By embedding a strain-sensitive sensor arranged in a spiral pattern within the wall of a drainage pipe, the method monitors the sensor's resistance change rate under vehicle vibration loads in real time. Combined with synchronously measured soil stress, and based on a pre-calibrated empirical model of moisture content-elastic modulus, the real-time volumetric moisture content of the roadbed soil is calculated. This invention solves the technical problem of traditional detection methods' difficulty in long-term, real-time monitoring of roadbed internal moisture content, achieving long-term, non-destructive monitoring of roadbed moisture content and providing an effective means for preventative road maintenance and stability assessment.

The invention provides a strain type piezoresistive effect sensitive element and a manufacturing method thereof.The sensitive element comprises an SOI wafer, a resistor, a second insulating layer and a second shielding layer, the SOI wafer comprises a first shielding layer and a first insulating layer, the resistor is arranged on the side, away from the first shielding layer, of the first insulating layer, and the second insulating layer is arranged on the side, away from the first shielding layer, of the second insulating layer; the second insulating layer is arranged on the side, away from the first shielding layer, of the first insulating layer and covers the resistor, and the second shielding layer covers the outer side of the second insulating layer and is located on the side, away from the first shielding layer, of the resistor; wherein at least one of the first shielding layer and the second shielding layer also surrounds the circumferential outer side of the resistor, so that the upper side, the lower side and the circumferential outer side of the resistor are surrounded by the first shielding layer and the second shielding layer, the external electromagnetic field shielding effect of the strain type piezoresistive effect sensitive element is improved, and the influence of an external electromagnetic field is avoided; therefore, the strain accuracy of the detected object and the measurement stability are improved.

The present invention belongs to the technical field of aerogel materials and specifically discloses a highly elastic PEDOT:PSS aerogel, a preparation method thereof, and an application thereof. The present invention first mixes a PEDOT:PSS aqueous solution with an acid and stirs to obtain a mixed solution containing bubble clusters; then subjecting the mixed solution to a hydrothermal reaction to obtain a hydrogel; and then subjecting the obtained hydrogel to sequential directional freeze-drying and annealing treatments to obtain a highly elastic PEDOT:PSS aerogel. The aerogel obtained by the present invention is a single-material pure PEDOT:PSS aerogel that does not require additional material reinforcement and has the characteristics of high porosity, good elasticity, and high conductivity, as well as high compressibility, fatigue resistance, and thermal insulation. Sensors based on pure PEDOT:PSS aerogel exhibit both piezoresistive and thermoelectric effects and can be used to manufacture high-performance temperature / pressure dual-mode sensors.

The invention relates to the technical field of MEMS sensors, in particular to a high-performance silicon piezoresistive pressure-sensitive flip chip. According to the invention, a nesting combination design of axial symmetry, central symmetry and symmetrical front and back piezoresistive sensitivity of a homodromous single-straight-strip piezoresistive bridge resistance sensitive structure and effect is adopted, so that the sensitive chip has the performance advantages of high linearity, high accuracy, consistent front and back piezoresistive effect sensitivity and non-linear symmetry, and strong overload pressure capability; the device is suitable for accurate measurement of negative gauge pressure, gauge pressure, negative absolute pressure, absolute pressure and differential pressure. The inverted packaging of the sensitive chip does not need isolation liquid sealing and movable lead bonding, the inherent frequency height and width advantage is suitable for high-frequency dynamic pressure measurement, and the long-term reliable working temperature upper limit can reach the Young modulus limiting temperature 556 DEG C of monocrystalline silicon.

A pressure sensing system that includes a dual-function foam is disclosed. The dual-function foam may be integrated into padding of a variety of objects to measure pressures and locations of pressures / strains exerted by a user on the padding. The dual-function foam may respond to a pressure / strain with a piezoelectric effect or a piezoresistive effect depending on the nature of the applied pressure / strain. Each effect may require different sensing approaches. Accordingly, the pressure sensor system may include a controller that is configurable into one of a plurality of operating modes based on the sensing approach suitable for the applied pressure / strain. One of the operating modes may be a sleep mode, which can reduce the power consumed by the controller when no pressure / strain is applied to the dual-function foam for a period.

The invention discloses a piezoelectric pressure sensor and a preparation method thereof. The piezoelectric pressure sensor includes: a substrate; the piezoelectric driving layer is positioned on one side of the substrate; the first cavity penetrates through at least part of the substrate along a first direction; the first direction is the thickness direction of the substrate; the limiting structure is located in the first cavity, and the distance between the limiting structure and the piezoelectric driving layer meets a preset distance range. According to the piezoelectric pressure sensor, the limiting structure used for limiting the piezoelectric driving layer is arranged in the first cavity, so that additional damping, resonance, stress, electrostatic noise and piezoresistive effect cannot be introduced through the arrangement of the limiting structure, and the influence of the limiting structure on the response speed and the measurement precision of the piezoelectric pressure sensor can be reduced; and compared with the scheme that the limiting structure is arranged on the mounting plate or the packaging structure, the size of the piezoelectric pressure sensor can be reduced.

A pressure sensing system that includes a dual-function foam is disclosed. The dual-function foam may be integrated into padding of a variety of objects to measure pressures and locations of pressures / strains exerted by a user on the padding. The dual-function foam may respond to a pressure / strain with a piezoelectric effect or a piezoresistive effect depending on the nature of the applied pressure / strain. Each effect may require different sensing approaches. Accordingly, the pressure sensor system may include a controller that is configurable into one of a plurality of operating modes based on the sensing approach suitable for the applied pressure / strain. One of the operating modes may be a sleep mode, which can reduce the power consumed by the controller when no pressure / strain is applied to the dual-function foam for a period.