scholarly journals A Direct-Writing Approach for Fabrication of CNT/Paper-Based Piezoresistive Pressure Sensors for Airflow Sensing

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 504
Author(s):  
Jinyan Chen ◽  
Van-Thai Tran ◽  
Hejun Du ◽  
Junshan Wang ◽  
Chao Chen
Keyword(s):  
High Performance ◽  
Pressure Sensors ◽  
Normal Pressure ◽  
Large Strains ◽  
Main Function ◽  
Direct Writing ◽  
Sensing Element ◽  
Tissue Paper ◽  
Loading Mode ◽  
Airflow Sensor

Airflow sensor is a crucial component for monitoring environmental airflow conditions in many engineering fields, especially in the field of aerospace engineering. However, conventional airflow sensors have been suffering from issues such as complexity and bulk in structures, high cost in fabrication and maintenance, and low stability and durability. In this work, we developed a facile direct-writing method for fabricating a low-cost piezoresistive element aiming at high-performance airflow sensing, in which a commercial pen was utilized to drop solutions of single-walled carbon nanotubes onto tissue paper to form a piezoresistive sensing element. The encapsulated piezoresistive element was tested for electromechanical properties under two loading modes: one loading mode is the so-called pressure mode in which the piezoresistive element is pressed by a normal pressure, and another mode is the so-called bending mode in which the piezoresistive element is bended as a cantilever beam. Unlike many other developed airflow sensors among which the sensing elements are normally employed as cantilever beams for facing winds, we designed a fin structure to be incorporated with the piezoresistive element for airflow sensing; the main function of the fin is to face winds instead of the piezoresistive element, and subsequently transfer and enlarge the airflow pressure to the piezoresistive element for the normal pressure loading mode. With this design, the piezoresistive element can also be protected by avoiding experiencing large strains and direct contact with external airflows so that the stability and durability of the sensor can be maintained. Moreover, we experimentally found that the performance parameters of the airflow sensor could be effectively tuned by varying the size of the fin structure. When the fin sizes of the airflow sensors were 20 mm, 30 mm, and 40 mm, the detection limits and sensitivities of the fabricated airflow sensors were measured as 8.2 m/s, 6.2 m/s, 3.2 m/s, 0.0121 (m/s)−2, 0.01657 (m/s)−2, and 0.02264 (m/s)−2, respectively. Therefore, the design of the fin structure could pave an easy way for adjusting the sensor performance without changing the sensor itself toward different application scenarios.

scholarly journals Study on the forming and sensing properties of laser-sintered TPU/CNT composites for plantar pressure sensors

2021 ◽  
Author(s):  
Yu Zhuang ◽  
Yanling Guo ◽  
Jian Li ◽  
Yueqiang Yu ◽  
Kaiyi Jiang ◽  
...  
Keyword(s):  
High Performance ◽  
Thermoplastic Polyurethane ◽  
Selective Laser Sintering ◽  
Conductive Polymer ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
High Sensitivity ◽  
Sensing Element ◽  
Resistance Response ◽  
Detection Range

AbstractConductive polymer composites (CPCs) combining with specific microstructures (micropores, microcracks, etc.) can exhibit unique resistance response changes, which can be widely regarded as an effective way to improve sensing performance. This study takes advantage of the characteristics of the formation of tiny pores between crystal grains during selective laser sintering (SLS) processing to introduce a microporous structure into the thermoplastic polyurethane (TPU)/carbon nanotube (CNT) sensing element to prepare a three-dimensional porous conductive structure. The effect of the SLS process on sensing sensitivity, accuracy, and density was studied, and its sensing and forming mechanism were discussed. By adjusting SLS process parameters to control the performance of porous structure sensor elements, a final TPU/CNT sensor element with a wide pressure detection range, high sensitivity, a fast response time, and good stability and durability was developed. Finally, the optimal performance of the developed flexible pressure sensor was successfully used to detect the pressure distribution of the human foot. This study provided a simple and effective research method to develop high-performance flexible pressure sensors.

CMOS-MEMS Based Current Mirror MOSFET Embedded Pressure Sensor for Healthcare and Biomedical Applications

2013 ◽  
Vol 647 ◽  
pp. 315-320 ◽  
Author(s):  
Pradeep Kumar Rathore ◽  
Brishbhan Singh Panwar
Keyword(s):  
Pressure Sensor ◽  
Biomedical Applications ◽  
Circuit Simulation ◽  
Applied Pressure ◽  
Pressure Sensors ◽  
Cmos Technology ◽  
Current Mirror ◽  
Sensing Element ◽  
Pressure Sensing ◽  
Cmos Mems

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.

Binary Spiky/Spherical Nanoparticle Films with Hierarchical Micro/Nanostructures for High-Performance Flexible Pressure Sensors

2020 ◽  
Vol 12 (52) ◽  
pp. 58403-58411
Author(s):  
Young-Ryul Kim ◽  
Minsoo P. Kim ◽  
Jonghwa Park ◽  
Youngoh Lee ◽  
Sujoy Kumar Ghosh ◽  
...  
Keyword(s):  
High Performance ◽  
Pressure Sensors ◽  
Nanoparticle Films ◽  
Flexible Pressure Sensors

Oxidized Ti3C2Tx film-based high-performance flexible pressure sensors

2021 ◽  
Author(s):  
Xiyao Fu ◽  
Depeng Wang ◽  
Lili Wang ◽  
Hao Xu ◽  
Valerii Shulga ◽  
...  
Keyword(s):  
High Performance ◽  
Pressure Sensors ◽  
Flexible Pressure Sensors

scholarly journals Reliable Fabrication of Graphene Nanostructure Based on e-Beam Irradiation of PMMA/Copper Composite Structure

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4634
Author(s):  
Kaixi Bi ◽  
Jiliang Mu ◽  
Wenping Geng ◽  
Linyu Mei ◽  
Siyuan Zhou ◽  
...  
Keyword(s):  
High Performance ◽  
Local Heating ◽  
Copper Substrate ◽  
Direct Writing ◽  
Resonant Structures ◽  
In Situ Preparation ◽  
Copper Composite ◽  
Graphene Nanostructure ◽  
Graphene Nanostructures

Graphene nanostructures are widely perceived as a promising material for fundamental components; their high-performance electronic properties offer the potential for the construction of graphene nanoelectronics. Numerous researchers have paid attention to the fabrication of graphene nanostructures, based on both top-down and bottom-up approaches. However, there are still some unavoidable challenges, such as smooth edges, uniform films without folds, and accurate dimension and location control. In this work, a direct writing method was reported for the in-situ preparation of a high-resolution graphene nanostructure of controllable size (the minimum feature size is about 15 nm), which combines the advantages of e-beam lithography and copper-catalyzed growth. By using the Fourier infrared absorption test, we found that the hydrogen and oxygen elements were disappearing due to knock-on displacement and the radiolysis effect. The graphene crystal is also formed via diffusion and the local heating effect between the e-beam and copper substrate, based on the Raman spectra test. This simple process for the in-situ synthesis of graphene nanostructures has many promising potential applications, including offering a way to make nanoelectrodes, NEMS cantilever resonant structures, nanophotonic devices and so on.

High-performance flexible all-solid-state aqueous rechargeable Zn–MnO2 microbatteries integrated with wearable pressure sensors

2018 ◽  
Vol 6 (30) ◽  
pp. 14594-14601 ◽  
Author(s):  
Bing He ◽  
Qichong Zhang ◽  
Lianhui Li ◽  
Juan Sun ◽  
Ping Man ◽  
...  
Keyword(s):  
Solid State ◽  
Real Time ◽  
Health Monitoring ◽  
High Performance ◽  
Pressure Sensors ◽  
Integrated System

A self-powering, multifunctional, miniaturized integrated system was designed to achieve real-time health monitoring both statically and dynamically.

Scalable High-Performance Ultraminiature Graphene Micro-Supercapacitors by a Hybrid Technique Combining Direct Writing and Controllable Microdroplet Transfer

2018 ◽  
Vol 10 (6) ◽  
pp. 5404-5412 ◽  
Author(s):  
Daozhi Shen ◽  
Guisheng Zou ◽  
Lei Liu ◽  
Wenzheng Zhao ◽  
Aiping Wu ◽  
...  
Keyword(s):  
High Performance ◽  
Hybrid Technique ◽  
Direct Writing

scholarly journals Polyaniline Nanofiber Wrapped Fabric for High Performance Flexible Pressure Sensors

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1120 ◽  
Author(s):  
Kangning Liu ◽  
Ziqiang Zhou ◽  
Xingwu Yan ◽  
Xiang Meng ◽  
Hua Tang ◽  
...  
Keyword(s):  
High Performance ◽  
Rational Design ◽  
Active Material ◽  
Pressure Sensors ◽  
Linear Range ◽  
Superior Performance ◽  
Wearable Electronics ◽  
Wide Linear Range ◽  
Polyaniline Nanofiber ◽  
Flexible Pressure Sensors

The rational design of high-performance flexible pressure sensors with both high sensitivity and wide linear range attracts great attention because of their potential applications in wearable electronics and human-machine interfaces. Here, polyaniline nanofiber wrapped nonwoven fabric was used as the active material to construct high performance, flexible, all fabric pressure sensors with a bottom interdigitated textile electrode. Due to the unique hierarchical structures, large surface roughness of the polyaniline coated fabric and high conductivity of the interdigitated textile electrodes, the obtained pressure sensor shows superior performance, including ultrahigh sensitivity of 46.48 kPa−1 in a wide linear range (<4.5 kPa), rapid response/relaxation time (7/16 ms) and low detection limit (0.46 Pa). Based on these merits, the practical applications in monitoring human physiological signals and detecting spatial distribution of subtle pressure are demonstrated, showing its potential for health monitoring as wearable electronics.

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