Novel silicone-based capacitive pressure sensors with high sensitivity for biomedical applications

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Khalil Arshak ◽  
Deirdre Morris ◽  
Olga Korostynska ◽  
Essa Jafer ◽  
Arousian Arshak ◽  
...  

Abstract In this work, an investigation of the pressure-sensing properties of a silicone rubber was conducted. Small amounts of carbon black were added to the silicone during fabrication and the effect on the sensitivity was explored. A full investigation of the mechanical and electrical properties of each composition shows that adding carbon black to the material greatly increases its sensitivity to pressure. This increase in sensitivity appears to be related to improvements in the material’s permittivity, which increases with carbon loading.

2013 ◽  
Vol 647 ◽  
pp. 315-320 ◽  
Author(s):  
Pradeep Kumar Rathore ◽  
Brishbhan Singh Panwar

This paper reports on the design and optimization of current mirror MOSFET embedded pressure sensor. A current mirror circuit with an output current of 1 mA integrated with a pressure sensing n-channel MOSFET has been designed using standard 5 µm CMOS technology. The channel region of the pressure sensing MOSFET forms the flexible diaphragm as well as the strain sensing element. The piezoresistive effect in MOSFET has been exploited for the calculation of strain induced carrier mobility variation. The output transistor of the current mirror forms the active pressure sensing MOSFET which produces a change in its drain current as a result of altered channel mobility under externally applied pressure. COMSOL Multiphysics is utilized for the simulation of pressure sensing structure and Tspice is employed to evaluate the characteristics of the current mirror pressure sensing circuit. Simulation results show that the pressure sensor has a sensitivity of 10.01 mV/MPa. The sensing structure has been optimized through simulation for enhancing the sensor sensitivity to 276.65 mV/MPa. These CMOS-MEMS based pressure sensors integrated with signal processing circuitry on the same chip can be used for healthcare and biomedical applications.


Author(s):  
Qiong Tian ◽  
Wenrong Yan ◽  
Tianding CHEN ◽  
Derek Ho

Pressure sensing electronics have gained great attention in human-machine interface, soft robotics, and wearable biomedical applications. However, existing sensor architectures are inadequate in overcoming the classic tradeoff between sensing range,...


Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 664 ◽  
Author(s):  
Junsong Hu ◽  
Junsheng Yu ◽  
Ying Li ◽  
Xiaoqing Liao ◽  
Xingwu Yan ◽  
...  

The reasonable design pattern of flexible pressure sensors with excellent performance and prominent features including high sensitivity and a relatively wide workable linear range has attracted significant attention owing to their potential application in the advanced wearable electronics and artificial intelligence fields. Herein, nano carbon black from kerosene soot, an atmospheric pollutant generated during the insufficient burning of hydrocarbon fuels, was utilized as the conductive material with a bottom interdigitated textile electrode screen printed using silver paste to construct a piezoresistive pressure sensor with prominent performance. Owing to the distinct loose porous structure, the lumpy surface roughness of the fabric electrodes, and the softness of polydimethylsiloxane, the piezoresistive pressure sensor exhibited superior detection performance, including high sensitivity (31.63 kPa−1 within the range of 0–2 kPa), a relatively large feasible range (0–15 kPa), a low detection limit (2.26 pa), and a rapid response time (15 ms). Thus, these sensors act as outstanding candidates for detecting the human physiological signal and large-scale limb movement, showing their broad range of application prospects in the advanced wearable electronics field.


2013 ◽  
Vol 86 (3) ◽  
pp. 423-448 ◽  
Author(s):  
Liliane Bokobza

ABSTRACT The reinforcement of elastomeric materials by addition of mineral fillers represents one of the most important aspects in the field of rubber science and technology. The improvement in mechanical properties arises from hydrodynamic effects depending mainly on the amount of filler and the aspect ratio of the particles and also on polymer–filler interactions depending on the surface characteristics of the filler particles and the chemical nature of the polymer. The past few years have seen the extensive use of nanometer-scale particles of different morphologies on account of the small size of the filler and the corresponding increase in the surface area that allow a considerable increase in mechanical properties even at very low filler loading. Among these nanoparticles, spherical particles (such as silica or titania) generated in situ by the sol-gel process and carbon nanotubes are typical examples of materials used as a nanosize reinforcing additive. Specific features of filled elastomers are discussed through the existing literature and through results of the author's research based on poly(dimethylsiloxane) filled with spherical silica or titania particles and on styrene–butadiene rubber filled with multiwall carbon nanotubes. The reinforcing ability of each type of filler is discussed in terms of morphology, state of dispersion (investigated by transmission electron microscopy, atomic force microscopy, small-angle neutron scattering), and mechanical and electrical properties. In addition, the use of molecular spectroscopies provides valuable information on the polymer–filler interface. Spherical silica and titania spherical particles are shown to exhibit two distinct morphologies, two different polymer–filler interfaces that influence the mechanical properties of the resulting materials. The superiority of carbon nanotubes over carbon black for mechanical reinforcement and electrical conduction is mainly attributed to their large aspect ratio rather than to strong polymer–filler interactions. The use of hybrid fillers (carbon nanotubes in addition to carbon black or silica, for example) has been shown to give promising results by promoting an enhancement of mechanical and electrical properties with regard to each single filler.


Nanoscale ◽  
2021 ◽  
Author(s):  
Yachu Zhang ◽  
Han Lin ◽  
Fei Meng ◽  
Huai Liu ◽  
David Mesa ◽  
...  

Wearable and highly sensitive pressure sensors are of great importance for robotics, health monitoring and biomedical applications. Simultaneously achieving high sensitivity within a broad working range, fast response time (within...


2008 ◽  
Vol 589 ◽  
pp. 179-184 ◽  
Author(s):  
László Valenta ◽  
Attila Bojtos

Silicone rubber is an essential construction material in food industry, medicine and in some fields of mechanical engineering, because it has good mechanical, electrical, biological and other special properties. One needs to know these material properties in order to develop silicone sensors. We performed several standard measurements for rubber, like tensile strength, cyclic tensile, bending, fatiguing, stress relaxation tests etc. To investigate the electrical properties, we measured the resistance of silicone during the mechanical tests. The paper summarizes the newest results of our research in connection with mechanical and electrical properties of conductive silicone rubber.


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