Ultra-sensitive wide-range small capacitive pressure sensor based on porous CCTO-PDMS membrane

Flexible and wearable pressure sensors have attracted significant attention owing to their roles in healthcare monitoring and human–machine interfaces. In this study, we introduce a wide-range, highly sensitive, stable, reversible, and biocompatible pressure sensor based on a porous Ecoflex with tilted air-gap-structured and carbonized cotton fabric (CCF) electrodes. The knitted structure of electrodes demonstrated the effectiveness of the proposed sensor in enhancing the pressure-sensing performance in comparison to a woven structure due to the inherent properties of naturally generated space. In addition, the presence of tilted air gaps in the porous elastomer provided high deformability, thereby significantly improving the sensor sensitivity compared to other dielectric structures that have no or vertical air gaps. The combination of knitted CCF electrodes and the porous dielectric with tilted air gaps achieved a sensitivity of 24.5 × 10−3 kPa−1 at 100 kPa, along with a wide detection range (1 MPa). It is also noteworthy that this novel method is low-cost, facile, scalable, and ecofriendly. Finally, the proposed sensor integrated into a smart glove detected human motions of grasping water cups, thus demonstrating its potential applications in wearable electronics.

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Flexible wide-range capacitive pressure sensor using micropore PE tape as template

Smart Materials and Structures ◽

10.1088/1361-665x/ab4ac6 ◽

2019 ◽

Vol 28 (11) ◽

pp. 115040 ◽

Cited By ~ 1

Author(s):

Qiang Zhang ◽

Wendan Jia ◽

Chao Ji ◽

Zhen Pei ◽

Zhu Jing ◽

...

Keyword(s):

Pressure Sensor ◽

Capacitive Pressure Sensor ◽

Wide Range

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Silicon Carbide MEMS Capacitive Pressure Sensor for Harsh Environments

Volume 10: Micro- and Nano-Systems Engineering and Packaging ◽

10.1115/imece2013-64764 ◽

2013 ◽

Cited By ~ 3

Author(s):

Zhibang Chen ◽

Wei Du ◽

Feng Zhao

Keyword(s):

Silicon Carbide ◽

Pressure Sensor ◽

Large Scale ◽

Applied Pressure ◽

High Sensitivity ◽

Capacitive Pressure Sensor ◽

Wide Range ◽

Sensor Structure ◽

Nuclear Station ◽

Oil Gas

In this paper, we investigated a new capacitive pressure sensor structure on a silicon carbide (SiC) platform for high sensitivity and harsh environment operation capability. The superior material properties of SiC ensure robustness of the new sensor to withstand large-scale pressure at high temperature and in chemical/biological medium. The sensor structure consists of a circular SiC diaphragm suspended by four arms over a SiC substrate, with design to enable diaphragm to deflect nearly uniformly with applied pressure. This configuration results in improved sensing properties. With high sensitivity and operation capability in hostile environment, this new pressure sensor is promising for use in a wide range of applications such as automotive, nuclear station, aerospace, and oil/gas exploration, etc.

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A Capacitive MEMS Pressure Sensor With Wavy Membrane and Linear Capacitance-Pressure Response

Volume 4: 24th Design for Manufacturing and the Life Cycle Conference; 13th International Conference on Micro- and Nanosystems ◽

10.1115/detc2019-98021 ◽

2019 ◽

Author(s):

Stephen Oke ◽

Mohammad Shavezipur

Keyword(s):

Pressure Sensor ◽

Ambient Pressure ◽

Pressure Sensors ◽

Wave Form ◽

Capacitive Pressure Sensor ◽

Working Pressure ◽

Sensing Applications ◽

Wide Range ◽

Capacitance Pressure ◽

Capacitive Mems

Abstract A novel structure for capacitive MEMS pressure sensors is presented that can be used for a wide range of pressure sensing applications. The sensor is designed such that its characteristic capacitance-pressure (C-P) response is highly linear and could cover a wide range of working pressure. A capacitive pressure sensor includes two capacitive electrodes, one patterned on the substrate and the other one suspended creating a sealed cavity. The suspended electrode acts as the pressure sensitive membrane in the device and undergoes out-of-plane deformation when there is a change in ambient pressure, resulting in a change in the device’s capacitance. The design presented in this work uses a wavy-shape membrane with controlled deformations to provide a highly linear C-P response. The wavy shape of the membrane can be fabricated using grey-scale mask and lithography. ANSYS APDL multiphysics solver is used to model and simulate the pressure sensor and optimize its response. The material used in the design and simulations of the pressure sensor is silicon carbide making this design suitable for harsh environment applications. The simulation results show that if the size and the shape of the wave form in the membrane are optimized, highly linear C-P response can be achieved and also its working pressure range can be extended.

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Porous Polydimethylsiloxane Elastomer Hybrid with Zinc Oxide Nanowire for Wearable, Wide-Range, and Low Detection Limit Capacitive Pressure Sensor

Nanomaterials ◽

10.3390/nano12020256 ◽

2022 ◽

Vol 12 (2) ◽

pp. 256

Author(s):

Gen-Wen Hsieh ◽

Liang-Cheng Shih ◽

Pei-Yuan Chen

Keyword(s):

Zinc Oxide ◽

Detection Limit ◽

Pressure Sensor ◽

Dielectric Layer ◽

Water Pressure ◽

Capacitive Pressure Sensor ◽

Wide Range ◽

Zinc Oxide Nanowire ◽

Polydimethylsiloxane Elastomer ◽

Nanocomposite Dielectric

We propose a flexible capacitive pressure sensor that utilizes porous polydimethylsiloxane elastomer with zinc oxide nanowire as nanocomposite dielectric layer via a simple porogen-assisted process. With the incorporation of nanowires into the porous elastomer, our capacitive pressure sensor is not only highly responsive to subtle stimuli but vigorously so to gentle touch and verbal stimulation from 0 to 50 kPa. The fabricated zinc oxide nanowire–porous polydimethylsiloxane sensor exhibits superior sensitivity of 0.717 kPa−1, 0.360 kPa−1, and 0.200 kPa−1 at the pressure regimes of 0–50 Pa, 50–1000 Pa, and 1000–3000 Pa, respectively, presenting an approximate enhancement by 21−100 times when compared to that of a flat polydimethylsiloxane device. The nanocomposite dielectric layer also reveals an ultralow detection limit of 1.0 Pa, good stability, and durability after 4000 loading–unloading cycles, making it capable of perception of various human motions, such as finger bending, calligraphy writing, throat vibration, and airflow blowing. A proof-of-concept trial in hydrostatic water pressure sensing has been demonstrated with the proposed sensors, which can detect tiny changes in water pressure and may be helpful for underwater sensing research. This work brings out the efficacy of constructing wearable capacitive pressure sensors based on a porous dielectric hybrid with stress-sensitive nanostructures, providing wide prospective applications in wearable electronics, health monitoring, and smart artificial robotics/prosthetics.

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Development of circuit solution and design of capacitive pressure sensor array for applied robotics

Robotics and Technical Cybernetics ◽

10.31776/rtcj.8406 ◽

2020 ◽

Vol 8 (4) ◽

pp. 296-307

Author(s):

Konstantin Krestovnikov ◽

Aleksei Erashov ◽

Аleksandr Bykov

Keyword(s):

Pressure Sensor ◽

Output Signal ◽

Sensor Array ◽

Applied Pressure ◽

Pressure Sensors ◽

Fine Tuning ◽

Capacitive Pressure Sensor ◽

Cell Parameters ◽

Linear Pattern ◽

Sensor Structure

This paper presents development of pressure sensor array with capacitance-type unit sensors, with scalable number of cells. Different assemblies of unit pressure sensors and their arrays were considered, their characteristics and fabrication methods were investigated. The structure of primary pressure transducer (PPT) array was presented; its operating principle of array was illustrated, calculated reference ratios were derived. The interface circuit, allowing to transform the changes in the primary transducer capacitance into voltage level variations, was proposed. A prototype sensor was implemented; the dependency of output signal power from the applied force was empirically obtained. In the range under 30 N it exhibited a linear pattern. The sensitivity of the array cells to the applied pressure is in the range 134.56..160.35. The measured drift of the output signals from the array cells after 10,000 loading cycles was 1.39%. For developed prototype of the pressure sensor array, based on the experimental data, the average signal-to-noise ratio over the cells was calculated, and equaled 63.47 dB. The proposed prototype was fabricated of easily available materials. It is relatively inexpensive and requires no fine-tuning of each individual cell. Capacitance-type operation type, compared to piezoresistive one, ensures greater stability of the output signal. The scalability and adjustability of cell parameters are achieved with layered sensor structure. The pressure sensor array, presented in this paper, can be utilized in various robotic systems.

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