Showing papers on "Piezoelectric sensor published in 2020"
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TL;DR: This review presents an overview of the recent developments in new intrinsically stretchable piezoelectric materials and rigid inorganic pieZoelectrics materials with novel stretchable structures for flexible and stretchable PiezoeLECTric sensors and energy harvesters.
190 citations
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TL;DR: Combined with those advantages of molecular ferroelectrics, such as light weight, easy and environment-friendly processing, and mechanical flexibility, (ATHP)2PbBr4 would be a competitive candidate for next-generation smart piezoelectric sensors in flexible devices, soft robotics, and biomedical devices.
Abstract: Piezoelectric sensors that can work under various conditions with superior performance are highly desirable with the arrival of the Internet of Things. For practical applications, a large piezoelectric voltage coefficient g and a high Curie temperature Tc are critical to the performance of piezoelectric sensors. Here, we report a two-dimensional perovskite ferroelectric (4-aminotetrahydropyran)2PbBr4 [(ATHP)2PbBr4] with a saturated polarization of 5.6 μC cm-2, high Tc of 503 K [above that of BaTiO3 (BTO, 393 K)], and extremely large g33 of 660.3 × 10-3 V m N-1 [much beyond that of Pb(Zr,Ti)O3 (PZT) ceramics (20 to 40 × 10-3 V m N-1), more than 2 times higher than that of poly(vinylidene fluoride) (PVDF, about 286.7 × 10-3 V m N-1)]. Combined with the advantages of molecular ferroelectrics, such as light weight, easy and environmentally friendly processing, and mechanical flexibility, (ATHP)2PbBr4 would be a competitive candidate for next-generation smart piezoelectric sensors in flexible devices, soft robotics, and biomedical devices.
135 citations
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TL;DR: This article presents standard methods to match the acoustic impedance of the piezoelectric sensors, actuators, and transducers with the surrounding wave propagation media.
Abstract: The coupling of waves between the piezoelectric generators, detectors, and propagating media is challenging due to mismatch in the acoustic properties. The mismatch leads to the reverberation of waves within the transducer, heating, low signal-to-noise ratio, and signal distortion. Acoustic impedance matching increases the coupling largely. This article presents standard methods to match the acoustic impedance of the piezoelectric sensors, actuators, and transducers with the surrounding wave propagation media. Acoustic matching methods utilizing active and passive materials have been discussed. Special materials such as nanocomposites, metamaterials, and metasurfaces as emerging materials have been presented. Emphasis is placed throughout the article to differentiate the difference between electric and acoustic impedance matching and the relation between the two. Comparison of various techniques is made with the discussion on capabilities, advantages, and disadvantages. Acoustic impedance matching for specific and uncommon applications has also been covered.
97 citations
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TL;DR: In this paper, a self-powered photo-active piezoelectric energy harvester was fabricated by a composite of room temperature processed all-inorganic cesium lead bromide (CsPbBr3) perovskite rod and polyvinylidene fluoride (PVDF) nanofiber.
67 citations
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20 Aug 2020TL;DR: In this paper, high-performance wearable electronic devices with the capability of converting mechanical force into electrical energy have been gaining increasing attention for biomedical monitoring applications, such as biomedical data collection.
Abstract: High-performance wearable electronic devices with the capability of converting mechanical force into electrical energy have been gaining increasing attention for biomedical monitoring applications....
59 citations
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TL;DR: In this paper, gallium nitride (GaN) was used as a sensing material, where the sensor was made by a simple layer transferring process after the removal of silicon substrate, and the output potential values of GaN with respect to gas pressure levels were 42.3, 76.8, 98.7, and 122.1 mV for 50, 100, 150, and 200 psi, respectively, well matched to simulated results.
Abstract: Piezoelectric materials are promising for pressure sensors in a variety of industrial applications such as automotive and petroleum fields. Typical piezoelectric sensors rely heavily on lead zirconate titanate (Pb[ZrxTi1-x]O3, PZT) transducers. However, for broader applications of piezoelectric sensors, the PZT is a suboptimal candidate due to its unstable output at temperatures above 200 °C and potential environmental hazard. A recent research objective is to produce a more effective, safer, and eco-friendly material than PZT for piezoelectric pressure sensors by incorporating lead-free materials, such as other ceramics or polymeric composites. Among lead-free materials, gallium nitride (GaN) has a notable piezoelectric coefficient and demonstrates the greatest potential to replace the PZT as a result of its performance in high temperature and pressure operating conditions. In this study, GaN thin film is used as a sensing material, where the sensor is made by a simple layer transferring process after the removal of silicon substrate. The output potential values of GaN with respect to gas pressure levels are 42.3, 76.8, 98.7, and 122.1 mV for 50, 100, 150, and 200 psi, respectively, well matched to simulated results. Additionally, the potentials measured at elevated temperatures produce reliable outputs at high temperatures up to 350 °C. Furthermore, the stability of sensor outputs at room temperature and elevated temperatures with various pressure levels was confirmed.
52 citations
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TL;DR: It is discovered that grain boundaries (GBs) in monolayer MoS2 can significantly enhance its piezoelectric proper-ty and is demonstrated its potential in self-powered precision sensors for in-situ detecting pressure changes in human blood for the health monitoring.
Abstract: Recent discovery of piezoelectricity that existed in two-dimensional (2D) layered materials represents a key milestone for flexible electronics and miniaturized and wearable devices. However, so far the reported piezoelectricity in these 2D layered materials is too weak to be used for any practical applications. In this work, we discovered that grain boundaries (GBs) in monolayer MoS2 can significantly enhance its piezoelectric property. The output power of piezoelectric devices made of the butterfly-shaped monolayer MoS2 was improved about 50% by the GB-induced piezoelectric effect. The enhanced piezoelectricity is attributed to the additional piezoelectric effect induced by the existence of deformable GBs which can promote polarization and generates spontaneous polarization with different piezoelectric coefficients along various directions. We further made a flexible piezoelectric device based on the 2D MoS2 with the GBs and demonstrated its potential application in self-powered precision sensors for in situ detecting pressure changes in human blood for health monitoring.
51 citations
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TL;DR: To account for the temperature effect on guided wave signals in complex structures, a significant amount of baseline measurements typically need to be collected over a large temperature range to se... as mentioned in this paper,...
Abstract: To account for the temperature effect on guided wave signals in complex structures, a significant amount of baseline measurements typically need to be collected over a large temperature range to se...
49 citations
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03 Jul 2020
TL;DR: In this article, the use of two types of polymer coating as protective layers on the sensor, specifi cally Polydimethylsiloxane (PDMS) and polyester, has been studied.
Abstract: It is critical to evaluate the quality of cementitious materials at its early age. Lead Zirconate Titanate (PZT) sensors, coupled with the electromechanical impedance (EMI) method, have proven to be a promising method for instantaneously monitoring the mechanical properties of cementitious materials. PZT is a piezoelectric ceramic with high piezoelectric properties and sensitivity, but its inherent brittleness limits its potential application in construction environments. To enhance the robust‐ ness of the sensor, this work has studied the use of two types of polymer coating as protective layers on the sensor, specifi‐ cally Polydimethylsiloxane (PDMS) and polyester. The effectiveness of piezoelectricity in polymer‐coated sensors is evaluated using a scanning laser Doppler vibrometer and an impedance analyzer. Finite element analysis has been conducted to simu‐ late the frequency response of sensors with different coating configurations. Moreover, this study has evaluated the feasi‐ bility of monitoring the growth of mortars’ mechanical properties over time using the proposed sensors with EMI technique. Based on the results, both polymer‐coated sensors have shown adequate sensitivity in capturing the change of mechanical properties in cementitious materials. The polyester coating performed better durability than PDMS coating as encapsulating materials. It has been concluded that the polymer‐coated, sensor‐based EMI method can be an effective nondestructive evaluation method for monitoring concrete properties in practical applications.
46 citations
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TL;DR: The piezoelectric sensitivity was significantly enhanced using carbon tape electrodes attached directly to the films instead of sandwiched electrodes, which produced a sensitivity of greater than 50 pC/N for the MBC nanocomposite film in the normal mode measurement.
36 citations
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TL;DR: A strategy based on peripheral circuits to improve the performance of piezoelectric sensors is proposed in the final part of this review.
Abstract: Piezoelectric sensors with high performance and low-to-zero power consumption meet the growing demand in the flexible microelectronic system with small size and low power consumption, which are promising in robotics and prosthetics, wearable devices and electronic skin. In this review, the development process, application scenarios and typical cases are discussed. In addition, several strategies to improve the performance of piezoelectric sensors are summed up: (1) material innovation: from piezoelectric semiconductor materials, inorganic piezoceramic materials, organic piezoelectric polymer, nanocomposite materials, to emerging and promising molecular ferroelectric materials. (2) designing microstructures on the surface of the piezoelectric materials to enlarge the contact area of piezoelectric materials under the applied force. (3) addition of dopants such as chemical elements and graphene in conventional piezoelectric materials. (4) developing piezoelectric transistors based on piezotronic effect. In addition, the principle, advantages, disadvantages and challenges of every strategy are discussed. Apart from that, the prospects and directions of piezoelectric sensors are predicted. In the future, the electronic sensors need to be embedded in the microelectronic systems to play the full part. Therefore, a strategy based on peripheral circuits to improve the performance of piezoelectric sensors is proposed in the final part of this review.
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TL;DR: Experimental results show that the PZT Layer can accurately detect structural impact and damage regions based on the SHM methods, demonstrating that the proposed PzT sensor network with shared signal transmission wires can significantly reduce the number of wires and monitoring channels and has great potential in aircraft smart skin applications for both passive and active SHM.
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TL;DR: In this article, the frequency analysis of a graphene platelets-reinforced composite (GPLRC) imperfect panel covered with piezoelectric sensor and actuator (PISA) is presented.
Abstract: The main point of the current study is that the frequency analysis of a graphene platelets–reinforced composite (GPLRC) imperfect panel covered with piezoelectric sensor and actuator (PISA) based o...
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TL;DR: Solid-state crystal growth (SSCG) has become a critical technique in the development of high-quality single crystal for piezoelectric devices as discussed by the authors, with high dielectric coefficients and low dielectrics losses that enable them to be utilised in high-end applications, such as medical imaging ultrasound.
Abstract: The forecasted restriction of lead containing materials in piezoelectric devices has created vast interest into the development of alternatives, i.e. lead-free systems. Since the discovery of improved properties, ferroelectric ceramics have dominated the commercial market for piezoelectric sensors, actuators and transducers. Relaxor ferroelectric single crystals are considered the premium piezoelectric materials, with high piezoelectric coefficients and low dielectric losses that enable them to be utilised in high-end applications, such as medical imaging ultrasounds. This review features the progress of lead-free single crystals that aim to replicate the remarkable piezoelectric properties that have been achieved in relaxor-PbTiO3 ferroelectric systems. Solid-state crystal growth (SSCG) has become a critical technique in the development of high-quality single crystals for such systems. SSCG is advantaged by its lower growth temperatures than conventional melt and solution growth techniques by producing crystals through a solid phase transformation of a polycrystalline matrix into a single crystal. This allows for higher chemical homogeneity and volatility control, while remaining a cost-effective growth method. The proposed theories of abnormal grain growth, which is the underlying mechanism that facilitates SSCG, will initially be discussed, followed by the challenges that must be controlled for continual high-quality single crystal growth. Given the correct polycrystalline microstructure and other processing parameters, large single crystals can be produced of incongruently melting systems that are unachievable using other techniques. This review provides a comparison of the state of the art of SSCG versus melt and solution growth techniques and concludes with the authors’ proposed focused points to inspire further improvements to both single crystal growth and piezoelectric properties.
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TL;DR: It is confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process.
Abstract: Poly(l-lactic acid) (PLLA) based piezoelectric polymers are gradually becoming the substitute for the conventional piezoelectric ceramic and polymeric materials due to their low cost and biodegradable, non-toxic, piezoelectric and non-pyroelectric nature. To improve the piezoelectric properties of melt-spun poly(l-lactic acid) (PLLA)/BaTiO3, we optimized the post-processing conditions to increase the proportion of the β crystalline phase. The α → β phase transition behaviour was determined by two-dimensional wide-angle x-ray diffraction and differential scanning calorimetry. The piezoelectric properties of PLLA/BaTiO3 fibres were characterised in their yarn and textile form through a tapping method. From these results, we confirmed that the crystalline phase transition of PLLA/BaTiO3 fibres was significantly enhanced under the optimised post-processing conditions at a draw ratio of 3 and temperature of 120 °C during the melt-spinning process. The results indicated that PLLA/BaTiO3 fibres could be a one of the material for organic-based piezoelectric sensors for application in textile-based wearable piezoelectric devices.
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TL;DR: Experimental and analytical investigations on sensor fault diagnosis for impedance-based SHM using the piezoelectric interface technique are presented, evidencing the feasibility of the novel impedance model for sensor diagnosis and structural integrity assessment.
Abstract: For a structural health monitoring (SHM) system, the operational functionality of sensors is critical for successful implementation of a damage identification process. This study presents experimental and analytical investigations on sensor fault diagnosis for impedance-based SHM using the piezoelectric interface technique. Firstly, the piezoelectric interface-based impedance monitoring is experimentally conducted on a steel bolted connection to investigate the effect of structural damage and sensor defect on electromechanical (EM) impedance responses. Based on the experimental analysis, sensor diagnostic approaches using EM impedance features are designed to distinguish the sensor defect from the structural damage. Next, a novel impedance model of the piezoelectric interface-driven system is proposed for the analytical investigation of sensor fault diagnosis. Various parameters are introduced into the EM impedance formulation to model the effect of shear-lag phenomenon, sensor breakage, sensor debonding, and structural damage. Finally, the proposed impedance model is used to analytically estimate the change in EM impedance responses induced by the structural damage and the sensor defect. The analytical results are found to be consistent with experimental observations, thus evidencing the feasibility of the novel impedance model for sensor diagnosis and structural integrity assessment. The study is expected to provide theoretical and experimental foundations for impedance monitoring practices, using the piezoelectric interface technique, with the existence of sensor faults.
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TL;DR: A good agreement between reference and predicted results proves that the wave responses at the piezoelectric transducers contain sufficient information in order to localize the impact position precisely.
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TL;DR: Structural damage detection using unmanned Structural Health Monitoring techniques is becoming the need of the day with the technologies available presently as mentioned in this paper, Sensors made of Lead Zirconate Titanate...
Abstract: Structural damage detection using unmanned Structural Health Monitoring techniques is becoming the need of the day with the technologies available presently. Sensors made of Lead Zirconate Titanate...
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TL;DR: It is proved that the load frequency is an important factor affecting the measurement accuracy of the sensor, which further enables us to design more suitable sensors for certain use scenarios.
Abstract: More and more researches have been carried out recently on Weigh-In-Motion (WIM) technology for solving the traffic safety problems caused by overload. In this article, we aim to study the measurement accuracy of the WIM system. Based on the electromechanical theory and elastic half-space method, we establish a theoretical model of multi-layer structure to investigate the correlation between the output voltage of the piezoelectric sensor and the applied force. In addition, we performed cyclic and moving load experiments to verify the accuracy of the analytical calculations. The load magnitude identified by this theoretical model matched the experiments very well, which shows that this model is effective for the WIM system. In addition, we proved that the load frequency is an important factor affecting the measurement accuracy of the sensor, which further enables us to design more suitable sensors for certain use scenarios.
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TL;DR: This work presents an adapting and spiking tactile sensor, based on a neuronal model and a piezoelectric field-effect transistor (PiezoFET), which enables said systems to receive information from the surrounding environment and provide encoded spike trains for neuromorphic hardware.
Abstract: The ongoing research on and development of increasingly intelligent artificial systems propels the need for bio inspired pressure sensitive spiking circuits. Here we present an adapting and spiking tactile sensor, based on a neuronal model and a piezoelectric field-effect transistor (PiezoFET). The piezoelectric sensor device consists of a metal-oxide semiconductor field-effect transistor comprising a piezoelectric aluminium-scandium-nitride (AlxSc1-xN) layer inside of the gate stack. The so augmented device is sensitive to mechanical stress. In combination with an analogue circuit, this sensor unit is capable of encoding the mechanical quantity into a series of spikes with an ongoing adaptation of the output frequency. This allows for a broad application in the context of robotic and neuromorphic systems, since it enables said systems to receive information from the surrounding environment and provide encoded spike trains for neuromorphic hardware. We present numerical and experimental results on this spiking and adapting tactile sensor.
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TL;DR: This study has revealed a facile methodology for fabricating large-scale piezoelectric devices using an asymmetrically engineered 2D WS2 structure and its device was found to be stable: it retained its piezOElectric performance even after a month in an ambient atmospheric condition.
Abstract: Piezoelectric materials are widely used as electromechanical couples for a variety of sensors and actuators in nanoscale electronic devices. The majority of piezoelectric devices display lateral patterning of counter electrodes beside active materials such as two-dimensional transition metal dichalcogenides (2D TMDs). As a result, their piezoelectric output response is strongly dependent on the lattice orientation of the 2D TMD crystal structure, limiting their piezoelectric properties. To overcome this issue, we fabricated a vertical sandwich design of a piezoelectric sensor with a conformal contact to enhance the overall piezoelectric performance. In addition, we enhanced the piezoelectric properties of 2D WS2 by carrying out a unique solvent-vapor annealing process to produce a sulfur-deficient WS2(1-x) structure that yielded a 3-fold higher piezoelectric response voltage (96.74 mV) than did pristine WS2 to a 3 kPa compression. Our device was also found to be stable: it retained its piezoelectric performance even after a month in an ambient atmospheric condition. Our study has revealed a facile methodology for fabricating large-scale piezoelectric devices using an asymmetrically engineered 2D WS2 structure.
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TL;DR: In this article, a modified non-bonded sensor (MNS) is proposed and evaluated for sensitivity in monitoring corrosion induced damage in pipeline segments in controlled laboratory setup through accelerated corrosion tests.
Abstract: In this paper, a piezoelectric sensor is used in its non-bonded configuration for non-destructive evaluation of a pipeline segment subjected to progressive corrosion damage. A new non-bonded sensor configuration, specially adapted for small diameter pipelines, known as modified non-bonded sensor (MNS), is proposed and evaluated. The new sensor configuration is evaluated for sensitivity in monitoring corrosion induced damage in pipeline segments in controlled laboratory setup through accelerated corrosion tests. The conventional surface-bonded piezo-sensor (SBPS) configuration is used as standard for comparison. Signature analysis using different methods is carried out in the study. Using the principles of the electro-mechanical impedance (EMI) technique, equivalent stiffness, damping and mass parameters are computed from the admittance signatures of both the configurations (MNS & SBPS) and compared. Experimental results show that piezo based a non-dimensional mass parameter from the MNS measurements are very effective in damage detection and quantification. The results are correlated with actual mass loss measurements and consequent corrosion rates are calibrated. The results clearly make case for practical usage of MNS configuration in corrosion detection and health monitoring of pipeline systems. The new MNS configuration proves to be a successful alternative to the conventional bonded piezo configuration.
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TL;DR: Both embedded and surface-mounted layers are shown to be an effective means of generating detectable wave scatter from damage and the proposed manufacturing alleviates difficulties associated with trimming edges of composites when embedding wires.
Abstract: An effective approach for an embedded piezo diagnostic layer into thick composite material is presented The effectiveness of the approach is assessed in comparison to the surface-mounted layer The proposed manufacturing alleviates difficulties associated with trimming edges of composites when embedding wires The Electro-Mechanical Impedance technique is used to access the integrity of the piezoelectric sensors bonding process Comparisons of ultrasonic guided waves are made between embedded and surface-mounted diagnostic layers and their penetration through and across the thickness of the composites Temperature influences with the range from -40 °C up to 80 °C on embedded and surface-mounted guided waves are investigated An investigation is carried out into the relationship between amplitude and time-of-flight with temperature at different excitation frequencies The temperature has significant but different effects on amplitude and phase-shift of guided waves for the embedded layer compared to the surface-mounted layer A Laser Doppler Vibrometer is used to identify the blue tack and impact damage Both embedded and surface-mounted layers are shown to be an effective means of generating detectable wave scatter from damage
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TL;DR: In this article, the excellent properties of advanced composite materials provide great opportunities for making industrial structures large-scale and intelligent, and the liquid composite molding process is suitable for mixtures.
Abstract: The excellent properties of advanced composite materials provide great opportunities for making industrial structures large-scale and intelligent. Liquid composite molding process is suitable for m...
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TL;DR: It is demonstrated that the loading can modify the vibration pattern in TIMs, allowing the proposed estimation, and offers the benefit of being a non-destructive technique (NDT) for industrial monitoring.
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TL;DR: In this paper, the role of normal-relaxor ferroelectric phase transition and morphotropic phase boundary on dielectric, piezoelectric and electrostrain properties is clarified.
Abstract: In this work, (Bi0.5K0.5)1-xSrxTiO3 compositions (x = 0.03∼0.18) are designed to clarify the role of normal-relaxor ferroelectric phase transition and morphotropic phase boundary on dielectric, piezoelectric and electrostrain properties. With increasing strontium content, tetragonal distortion decreases and tetragonal and pseudocubic phases coexist in 0.09 ≤ x ≤ 0.15 compositions; the spontaneous phase-transition temperature and curie temperature decrease, as certified by phase-structure, dielectric properties and Raman spectra analysis. Optimized piezoelectric constant ∼106 pC/N and electrostrain ∼0.17 % are obtained for (Bi0.5K0.5)0.88Sr0.12TiO3 composition. Piezoelectric force microscopic technique is exploited to clarify the origin of enhancement in macroscopic performances. Increase in temperature enhances ferroelectric performance and a large strain value ∼0.25 % with low hysteresis ∼27 % are obtained at 140 °C for the optimized composition, which are believed to originate from electric-field induced relaxor-to-ferroelectric phase transition with thermally-activated reduced energy barriers. This work clearly demonstrates that lead-free Bi0.5K0.5TiO3-based ceramics are another promising bismuth-based species in applications of piezoelectric sensors and actuators.
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TL;DR: A piezoelectric sensor combining a pin-type module with excellent monitoring in the depth direction by spring is developed, and the surface topography is reconstructed through highly accurate measurement results, similar to a human.
Abstract: Haptic sensors based on piezoelectric sensor arrays with pin-type modules which have high responses and dynamic sensing capabilities are designed and studied for surface topography measurements. Unlike the human finger, most flexible tactile sensor designs do not detect the depth information of surfaces well, which change at the mm level despite the fact that they have a good sensitivity for pressure or force. To enhance the ability to detect depth information of the surfaces of objects, a piezoelectric sensor combining a pin-type module with excellent monitoring in the depth direction by spring is developed in this paper. Because spike types of piezoelectric signals do not match a specific surface topography directly, a signal processing method that reconstructs the surface topography is studied considering the piezoelectric working principle and spring dynamics. According to the sensor design, it can detect 3 mm depth changes with a two-dimensional plane structure at mm-level resolutions. The results show that the proposed sensor could measure various shapes and depth profiles precisely via a sliding motion, and the surface topography is reconstructed through highly accurate measurement results, similar to a human.
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TL;DR: In this article, a piezoelectric sensor is designed in the form of a vertex-attached triangular beam made of Polyvinylidene fluoride (PVDF) and Polydimethylsiloxane (PDMS).
Abstract: In this paper, a novel piezoelectric sensor is presented for patient's breath monitoring applications. Breath rate monitoring is important especially for the new coronavirus patients. In this work, a piezoelectric sensor is designed in the form of a vertex-attached triangular beam made of Polyvinylidene fluoride (PVDF) and Polydimethylsiloxane (PDMS). It exploits chest displacement to distinguish breathing vibrations. The device shape and dimensions have been designed for low frequency operation. The output respiration signal is amplified using a low power charge amplifier circuit. The sensor can be placed in a vest and fastened as a belt, or be attached to the chest by a tape. A low pass filter is used to eliminate the noise from the environment and body movement. Among the most important features are high accuracy, low resonance frequency to distinguish chest movement, low weight, low cost, portability, and reliability. Simulation of the designed sensor using COMSOL shows output voltage of 1 V at breathing frequency of 0.2 Hz.