Pressure-sensitive Structure Research Articles

Characteristic analysis of a line-touch mode capacitive pressure-sensitive structure

Characteristic analysis of a line-touch mode capacitive pressure-sensitive structure

Study on pressure sensitive properties of diaphragm made of a kind of mechanochromic material

A new type of mechanochromic material was synthesized and fabricated into the pressure sensitive diaphragm. The pressure-deflection characteristics of the diaphragm were studied by establishing the pressure-deflection model, and then was verified by experiment. An experiment platform of optical detection was built to study the pressure-spectral characteristics of the diaphragm when it sensing pressure. On this basis, a gas pressure probe using this sensitive diaphragm was designed and fabricated, and the pressure experiment platform was built to test the performance of this pressure probe. This study provides an important theoretical and experimental reference for the design, optimization and further industrial application research of the pressure-sensitive structure or sensor using the mechanochromic material.

Study on a differential pressure microflow sensor on microfluidic chip

Based on the principle of differential pressure flow measurement, graphene film was used to measure the differential pressure in the micro channel of microfluidic chip and finally to obtain the micro flow rates. The relationship between differential pressure and flow rate in micro channel was studied and validated by CFD simulation. The fiber F-P cavity using graphene film was fabricated as the pressure sensitive structure, and the relationship between the measured pressure and the optical power output from the pressure sensitive structures was studied. The mechanism model used to measure the micro flow rates in the micro channel of microfluidic chip was established, and a sample of micro flow sensor was fabricated. The relationship between various quantities in the process of converting flow rate to optical power was verified through experiments, and the mechanism model established was verified. The experimental results demonstrate that fabricated sample could achieve accurate measurement of micro flow rate in the micro channel of microfluidic chip.

Real-Time Monitoring of Tire Condition with Fast Detection Passive and Wireless TPMS

<div class="section abstract"><div class="htmlview paragraph">Accurate tire pressure monitoring system (TPMS) is of great practical importance and the reliability and safety of its power supply module has great concern. The piezoelectric-based surface acoustic wave (SAW) sensor is considered to have great potential in this field because of its passive, wireless and small size advantages. This paper presents the application of passive and wireless SAW sensors for real-time tire condition monitoring. The pressure sensitive structure is optimized and a three-resonator structure is also designed sensing temperature and pressure. Furthermore, a fast detection system is developed to realize high-speed signal acquisition. At last, experiments are executed and the SAW temperature and pressure sensor property is measured. The results show that the designed SAW sensor can realize real-time monitoring of tire condition; the temperature measurement range can reach -40~120°C with an accuracy of ±1°C; the pressure measurement range can reach 0~2MPa with an accuracy of 0.2MPa. This paper indicates the wireless and passive SAW temperature and pressure sensor system has the potential for application in real-time monitoring of tire condition.</div></div>

Characteristic analysis of a capacitive pressure-sensitive structure with linkage film

In this paper, a capacitive pressure-sensitive structure with linkage film is proposed to expand the linear response range and linearity of the touch mode capacitive pressure-sensitive structure. In its construct, the top and bottom electrode plates are both sensitive to pressure and movable, thereby adjusting the way of contact and improving the performance. Through the simulation with the finite-elements method, characteristics of the capacitive pressure-sensitive structure with linkage film are analyzed. Results indicate that when compared to the touch mode capacitive pressure-sensitive structure, the linear response range of the proposal is more than doubled, and its nonlinearity can be significantly decreased.

A High Compressibility Pressure-Sensitive Structure Based on CB@PU Yarn Network.

In this work, a piezoresistive sensor structure based on carbon black (CB)@polyurethane (PU) yarn material was developed. Specifically, CB@PU yarn was constructed by the polymer-mediated water-based electrostatic deposition method. The distribution of the yarn was artificially controlled to fabricate conductive networks. The CB conductive layer was efficiently supported by the net-like structure of PU yarn, thus generating collaborative advantage. The as-fabricated pressure sensor not only displayed compressibility of over 97%, but also detected a wide pressure change from 25 Pa to 20 kPa. Furthermore, this sensor exhibited response time of less than 70 ms and reproducibility of over 10,000 cycles. The advantages of the CB@PU network ensured this pressure-sensitive structure enormous potential application in pressure sensitive equipment.

A Passive Pressure Sensor Fabricated by Post-Fire Metallization on Zirconia Ceramic for High-Temperature Applications

A high-temperature pressure sensor realized by the post-fire metallization on zirconia ceramic is presented. The pressure signal can be read out wirelessly through the magnetic coupling between the reader antenna and the sensor due to that the sensor is equivalent to an inductive-capacitive (LC) resonance circuit which has a pressure-sensitive resonance frequency. Considering the excellent mechanical properties in high-temperature environment, multilayered zirconia ceramic tapes were used to fabricate the pressure-sensitive structure. Owing to its low resistivity, sliver paste was chosen to form the electrical circuit via post-fire metallization, thereby enhancing the quality factor compared to sensors fabricated by cofiring with a high-melting-point metal such as platinum, tungsten or manganese. The design, fabrication, and experiments are demonstrated and discussed in detail. Experimental results showed that the sensor can operate at 600 °C with quite good coupling. Furthermore, the average sensitivity is as high as 790 kHz/bar within the measurement range between 0 and 1 Bar.

Scale-reduction rule without drop in the sensitivity of a silicon-based guided-wave optical pressure sensor using a micromachined diaphragm

In this study, an original scale-reduction rule without a drop in the sensitivity of a guided-wave optical pressure sensor was obtained using a micromachined diaphragm. The sensor has a rectangular diaphragm as a pressure-sensitive structure and a sensing waveguide across the diaphragm. Its sensitivity is theoretically known to be strongly dependent on the dimensions of the diaphragm. According to the theoretical results, the sensitivity can be kept constant even if the diaphragm dimensions are reduced as long as both the aspect ratio and the characteristic length of the diaphragm remain constant. Here, the characteristic length is introduced as the cube of either width or length of the rectangular diaphragm divided by the square of its thickness. Such a scale-reduction rule would be very useful for miniaturizing a sensor without reducing sensitivity, although it has not been experimentally confirmed. In this study, the scale-reduction rule was experimentally examined using three fabricated sensors with the same aspect ratio and the same characteristic length. The measured sensitivities of the three sensors were quite similar to each other, as theoretically predicted.