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In this work, we propose and demonstrate a flexible capacitive tactile sensor array based on graphene served as electrodes. The sensor array consists of 3 × 3 units with 3 mm spatial resolution, similar to that of human skin. Each unit has three layers. The middle layer with microstructured PDMS served as an insulator is sandwiched by two perpendicular graphene-based electrodes. The size of each unit is 3 mm × 3 mm and the initial capacitance is about 0.2 pF. High sensitivities of 0.73 kPa${}^{-1}$ between 0 and 1.2 kPa and 0.26 kPa${}^{-1}$ between 1.2 and 2.5 kPa were achieved on the fabricated graphene pressure sensors. The proposed flexible pressure sensor array shows a great potential on the application of electric skin or 3D touch control.

To further improve the sensitivity temperature characteristics of pressure sensor, a kind of pressure sensor taking nanopolysilicon thin films as piezoresistors is proposed in this paper. On the basis of the microstructure analysis by X-ray diffraction (XRD) and scanning electron microscope (SEM) tests, the preparing process of nanopolysilicon thin films is optimized. The effects of film thickness and annealing temperature on the micro-structure of nanopolysilicon thin films were studied, respectively. In order to realize the measurement of external pressure, four nanopolysilicon thin films resistors were arranged at the edges of square silicon diaphragm connected to a Wheatstone bridge, and the chip of the sensor was designed and fabricated on a $〈100〉$ orientation silicon wafer by microelectromechanical system (MEMS) technology. Experimental result shows that when $I$ = 6.80 mA, the sensitivity of the sensor PS-1 is 0.308 mV/kPa, and the temperature coefficient of sensitivity (TCS) is about −1742 ppm/${}^{\circ }$C in the range of −40–140${}^{\circ }$C. It is possible to obviously improve the sensitivity temperature characteristics of pressure sensor by the proposed sensors.

A high-sensitivity and high-transmittance flexible pressure sensor is presented in this paper. Using polydimethylsiloxane (PDMS) sensing film to cover indium tin oxide (ITO) electrodes interdigitated on the polyethylene terephthalate (PET) substrate, an interdigital capacitance (IDC) structure is constructed. The pressure and proximity sensing characteristics of the fabricated IDC sensor are investigated. The experiment results show that the IDC sensor has the piecewise linear function in different pressure range, especially sensitive to the low-pressure range with the pressure sensitivity of 6.64 kPa${}^{-1}$. Moreover, it has a good repeatability with the maximum error rate of 2.73% and a high transmittance over 90% in the wavelength range from 400 nm to 800 nm. As a human finger approaches or leaves, the proximity sensing characteristic emerges, with a maximum sensing distance of about 20 cm.

In order to further explore the intelligent research of the pressure sensor in the pipeline, based on the existing pipeline detection methods of the Internet of Things (IoT), the signal processing method and correction research in the wireless sensor network of the IoT are explored. A multi-pressure sensor detection method of negative pressure wave is proposed. Scientific and intelligent means are used to explore the pipeline remote intelligent detection. The specific research results are as follows. In the simulation study, when the working condition of pump station 1# changes, the pressure wave first reaches A₁ and B₂ sensors, and finally reaches C₁ and C₂ sensors. If there is leakage in the pipeline, the simulation results show that when the pressure of pump station rises to 5MPa, the pressure of B₁ and B₂ test points decreases to about 4.9MPa, and the pressure of A₁, A₂, C₁ and C₂ test points is about 3MPa; when the pressure of the pump station drops to 3MPa, the pressure of all test points decreases. Generally speaking, the pressure of the front-end pressure sensor of the pump station is basically unchanged while the pressure of the back end increases when the pressure increases; when the pressure decreases, the pressure of the front-end pressure sensor of the pump station is basically unchanged while the pressure of all the back-end pressure sensor decreases. After correction, the signal data is obviously smooth and the error is obviously reduced. This study can provide scientific and effective reference for the pressure monitoring of IoT sensor network.

Objective: Fetal movement (FM) is one of the objective phenomena of fetal life. The decrease of FM is a clinical indicator of fetal hypoxia. A fetal motion detection method is based on multiple pressure sensors and multi features. Methods: Collecting the abdominal data of pregnant women using multi-pressure sensors, preprocessing the signal with a digital filter, extracting the time–frequency characteristics of FM signal. The designed classifier is used for recognition of the extracted features. Results: The detection system used for FM time series can provide reliable results with a detection rate of 93.0% and a positive rate is 75.9%. Conclusion: The portable detection system proposed in this paper is a good alternative that will optimize medical use, professionals and hospital resources and has potential application prospects in the field of home electronic medical treatment.

To ensure the smoothness of working flow on the shop floor, workers need excellent and healthy physical conditions. However, some people with disabilities, especially those who have lost their limbs, will have difficulty carrying out the production-related activities. These problems become the background of this paper to design a prosthetic hand made by 3D printing technique. Nine servo motor units actuate all the joints and Arduino is applied as a microcontroller. This paper mainly discusses the design of the kinematics model in the hand, electrical system, and basic movements produced by this prosthetic hand. In addition, patterns of gripping are analyzed and compared with the 3D design. The use of servo motors in each joint of the prosthetic hand can be an advantage to increase the variety of motion in it compared with the design using a pull-string force system. Finally, this paper proposes the idea of future development of the hand design, to achieve a more versatile motion of each finger.

A new Fabry-Perot (FP) microcavity structure with a novel single deeply corrugated diaphragm (SDCD) is presented for use in pressure sensing. The mechanical behavior of the SDCD structure, as well as the key design parameters involved in the proposed FP microcavity to be better realized as a pressure sensor are simulated numerically and studied analytically. The FP microcavity is fabricated on a single-chip using both surface and bulk micromachining techniques. The preliminary characteristics of the FP microcavity show encouraging results.

Piezoelectric materials are widely applied in electronic components due to their ability to couple electric and mechanical fields. For the piezoelectric thin plate as a pressure sensor, we extend the modified first-order piezoelectric plate theory to explore the nonlinear solution of electric potential and discuss the relevant regulation mechanisms. Based on the piezoelectric effect, the electric potential generated by deformation is not linear with thickness. A quadratic function of electric potential across thickness is introduced. However, the electric potential on upper and lower electrodes is an unknown constant, which can be determined by the nonlinear complementary equation based on the Gauss theorem. It is shown that the nonlinear results of electric potential are consistent with outcomes by the three-dimensional finite element method. Furthermore, relevant regulation mechanisms are discussed on electric potential, including supported conditions, plate thickness, and load area. In addition, the influence of load locations on the electric potential response is analyzed. It is expected that these findings will be instructive to the structural design of piezoelectric pressure sensors.

In this work, antimony trioxide nanoparticles (Sb₂O₃NPs)-doped polyvinyl alcohol (PVA${}_{0.75}$) and polyvinyl pyrrolidone (PVP${}_{0.25}$) (i.e., PVAP@$x$Sb₂O₃NPs, $x=0,0.02$, and 0.04) composite films were prepared using the casting method. Light optical microscopy (LOM), scanning electron microscopy (SEM), and Fourier infrared spectrums (FTIR) were used to investigate PVAP@$x$Sb₂O₃NPs films. Sb₂O₃NPs were well dispersed within the matrix. FTIR showed a strong interaction between the matrix material and NPs. The density increased by up to 75% after adding 0.04wt.% of Sb₂O₃NPs. The mechanical ultrasound properties (MUS) were measured with different ultrasound frequencies in the ranges of (25, 30, 35, 40 and 45kHz). MUS coefficients such as ultrasonic velocity, absorption coefficient, and bulk modules were significantly improved after the impact of NPs by up to 20%, 115% and 230%, respectively. The reduction of electrical properties such as dielectric and loss constant was associated with an increase in frequency. The dielectric constant of PVAP@Sb₂O₃NPs was increased by about 80% after loading. AC electrical conductivity revealed an improvement with an increase in frequency and loading ratio. The results demonstrate a promising material for electromechanical, energy harvesting, and pressure sensor applications.

High-performance pressure sensors have caused widespread concern due to the potential applications in 3D-touch technology and wearable electronic devices. Herein, a new type of graphene pressure sensor based on the glass fiber surfacing mat coated with graphene oxide aqueous solution by a spray-vacuum filtration method and HI acid reduction method is reported. It is a simple and highly effective method to reduce graphene oxide films into highly conductive graphene films without destroying their integrity and flexibility at a low temperature based on the nucleophilic substitution reaction. The FTIR, SEM and conductivity tests indicate that the optimum time for graphene oxide to be reduced is 30min, under this condition enter the epoxy group has been reacted without damaging the regular sp² hybrid C atom structure in graphene. The conductivity of the graphene pressure sensor is increased significantly to 23260S/m. The monotonic compressing test for 100Pa/s and the test of the metal block placement and removal demonstrate that the sensor exhibits relatively high linearity of 99.74% between the response and pressure, the advantage makes the sensor monitor pressure more accurately. More importantly, the pressure sensor based on the glass fiber surfacing mat coated with graphene shows extremely high sensitivity (0.169${\text{kPa}}^{-1}$), fast response time (251ms) and good stability for 1000 cycles. Based on its superior performance, it also demonstrates potential applications in measuring pressure and human body’s motions.

With the promising applications in artificial intelligence systems and wearable health care devices, great efforts have been devoted to develop advanced pressure sensors. Graphene-based materials are promising pressure sensor materials due to the excellent electrical conductivity, outstanding mechanical properties and large surface area. This review summarizes the recent advances and progress in graphene and graphene-based pressure sensors. Perspectives and challenges in this exciting field are also highlighted and discussed.

Arterial compliance is defined as the variation of arterial vessel diameter under the blood pressure. This paper introduces the architecture of a brand-new compliance measurement. Two techniques are used: one is to use pressure feedback control and then obtain the variation of arterial vessel diameter at wrist; the other is to detect the delay time between two adjacent pressures and then calculate the downstream blood pressure according to the upstream blood pressure and delay time. The above information can easily compute the dynamic nonlinear arterial compliance. Therefore, the instrument comprises of two pressure sensors: one is fixed and the other is sliding upward and downward by a peizo-actuator. The piezo-actuator is imposed a strain gauge which senses the displacement of the actuator, or the variation of arterial vessel diameter. The design philosophy and fabrication of this instrument are present.

The static characteristics of the conductive rubber pressure sensor are very important in design, manufacturing and use process, and usually index of sensor static characteristics calculation requires manual calculation. However, in the application of study of carbon black filled conductive rubber pressure sensor, the workload is larger, and the efficiency is very low with its reliability being questionable. In this paper, carbon black filled conductive rubber samples and sensor arrays were prepared. It introduces the definition and calculation method of the static characteristics of the conductive rubber pressure sensor, including measurement range, linearity, sensitivity and hysteresis, and realizes that the automatic calculation of the static characteristic and the display of the calibration curve with the data processed by MATLAB. The test results show the algorithm and the feasibility of the program, which can proceed the static characteristics evaluation of pressure sensor simply and intuitively and provide the theory and research foundation for the application of the composite conductive polymer material in the flexible sensor.

The paper mainly aims at cross sensitivity problems in the measurement process with pressure sensor. Cross sensitivity problems are mainly manifested in the following aspects: pressure measurement is affected by target quantity and interfered by non-target quantity synchronously, such as temperature and other factors. New thought is provided for sensor data fusion due to continuous development of artificial neural network technology. In the paper, multi-sensor data fusion algorithm based on BP neural network is proposed on the basis of technology for studying commonly used data fusion methods. Influence of non-target quantity can be eliminated through BP neural network algorithm under the precondition of fully considering non-target quantities, such as temperature, etc., thereby improving measurement precision of pressure sensor.

This paper investigated novel wireless RF pressure sensor fabricated with SU-8 polymer. To achieve highly simplified fabrication processes and designs for high-reliable operation, a passive wireless sensors were researched. SU-8 polymer-based micro pressure sensor was fabricated by micro-electro-mechenical system (MEMS) based batch process. The sensor consists of an inductor (L) interconnected with pressure-variable capacitor (C) to form a LC resonant circuit. Fabricated devices measure 4 × 3 mm² in size and houses 9 turns of Cu electro-plated 100 nH coil. In this system, RF signal was transmitted from external antenna to the fabricated LC resonator. By detecting this abrupt resonant frequency shift of the fabricated device, the pressure change of the device can be measured by wireless method.