Skin-Inspired Pressure Sensor with MXene/P(VDF-TrFE-CFE) as Active Layer for Wearable Electronics

Multi-functional electronic skin is of paramount significance for wearable electronics in health monitoring, medical analysis, and human-machine interfacing systems. In order to achieve the function of natural skin, mechanical sensing with high sensitivity is an important feature of electronic skin. Inspired by the spinosum structure under the skin, herein, we fabricate a new capacitive pressure sensor with two-dimensional transition-metal carbides and nitrides (MXene) and ferroelectric polymer (P(VDF-TrFE-CFE)) as an active layer and micropatterned Cr-Au deposited on polydimethylsiloxane as flexible electrodes. Such a method is facile, effective, easily operated, and low-cost. The device design provides great capacitive change as a consequence of large deformation under pressure. Benefiting from the randomly distributed microstructure and high dielectric constant of the active layer, the device demonstrates high sensitivity with great linearity (16.0 kPa−1 for less than 10 kPa), that is, a low detection limit of 8.9 Pa, and quick response. A series of dynamic physiological signals, including typing, knuckle motion, and voice recognition can be facilely detected, making it a competitive candidate in the field of wearable electronics.

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Highly responsive screen-printed asymmetric pressure sensor based on laser-induced graphene

Journal of Micromechanics and Microengineering ◽

10.1088/1361-6439/ac388d ◽

2021 ◽

Author(s):

Jiang Zhao ◽

Jiahao Gui ◽

Jinsong Luo ◽

Jing Gao ◽

Caidong Zheng ◽

...

Keyword(s):

Pressure Sensor ◽

Screen Printing ◽

Large Scale ◽

Low Cost ◽

Pressure Sensors ◽

High Sensitivity ◽

Wearable Electronics ◽

Integrated Sensor ◽

Patterned Electrodes ◽

Screen Printed

Abstract Graphene-based pressure sensors have received extensive attention in wearable devices. However, reliable, low-cost, and large-scale preparation of structurally stable graphene electrodes for flexible pressure sensors is still a challenge. Herein, for the first time, laser-induced graphene (LIG) powder are prepared into screen printing ink, and shape-controllable LIG patterned electrodes can be obtained on various substrates using a facile screen printing process, and a novel asymmetric pressure sensor composed of the resulting screen-printed LIG electrodes has been developed. Benefit from the 3D porous structure of LIG, the as-prepared flexible LIG screen-printed asymmetric pressure sensor has super sensing properties with a high sensitivity of 1.86 kPa−1, low detection limit of about 3.4 Pa, short response time, and long cycle durability. Such excellent sensing performances give our flexible asymmetric LIG screen-printed pressure sensor the ability to realize real-time detection of tiny body physiological movements (such as wrist pulse and pronunciation action). Besides, the integrated sensor array has a multi-touch function. This work could stimulate an appropriate approach to designing shape-controllable LIG screen-printed patterned electrodes on various flexible substrates to adapt the specific needs of fulfilling compatibility and modular integration for potential application prospects in wearable electronics.

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High-sensitivity, fast-response flexible pressure sensor for electronic skin using direct writing printing

RSC Advances ◽

10.1039/d0ra04431h ◽

2020 ◽

Vol 10 (44) ◽

pp. 26188-26196 ◽

Cited By ~ 2

Author(s):

Xiaojun Chen ◽

Xitong Lin ◽

Deyun Mo ◽

Xiaoqun Xia ◽

Manfeng Gong ◽

...

Keyword(s):

Human Computer Interaction ◽

Pressure Sensor ◽

High Sensitivity ◽

Fast Response ◽

Wearable Electronics ◽

Direct Writing ◽

Electronic Skin ◽

Medical Health ◽

Flexible Pressure Sensor ◽

Health Diagnosis

Bionic electronic skin with human sensory capabilities has attracted extensive research interest, which has been applied in the fields of medical health diagnosis, wearable electronics, human–computer interaction, and bionic prosthetics.

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Flexible Pressure Sensor Based on Photo Paper-Molded Micro-Structural AgNWs/PDMS Electrode

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.748.1 ◽

2015 ◽

Vol 748 ◽

pp. 1-4 ◽

Cited By ~ 1

Author(s):

Li Xin Mo ◽

Yu Qun Hou ◽

Qing Bin Zhai ◽

Wen Guan Zhang ◽

Lu Hai Li

Keyword(s):

Pressure Sensor ◽

Silver Nanowires ◽

Low Cost ◽

Flexible Substrate ◽

High Sensitivity ◽

Low Energy ◽

Capacitive Pressure Sensor ◽

Micro Structure ◽

Energy Consuming ◽

Flexible Pressure Sensor

The novel flexible pressure sensor with skin-like stretchability and sensibility has attracted tremendous attention in academic and industrial world in recent years. And it also has demonstrated great potential in the applications of electronic skin and wearable devices. It is significant and challenging to develop a highly sensitive flexible pressure sensor with a simple, low energy consuming and low cost method. In this paper, the silver nanowires (AgNWs) as electrode material were synthesized by polyol process. The polydimethylsiloxane (PDMS) was chosen as a flexible substrate and polyimide (PI) film as dielectric layer. The AgNWs based electrode was prepared in two methods. One is coating the AgNWs on photographic paper followed by in situ PDMS curing. Another one is suction filtration of the AgNWs suspension followed by glass slide transfer and PDMS curing. Then the capacitive pressure sensor was packaged in a sandwich structure with two face to face electrodes and a PI film in the middle. The sensitivity of the sensor as well as the micro-structure of the electrodes was compared and studied. The results indicate that the roughness of the electrode based on AgNWs/PDMS micro-structure plays an important role in the sensitivity of sensor. The as-prepared flexible pressure sensor demonstrates high sensitivity of 0.65kPa-1. In addition, the fabrication method is simple, low energy consuming and low cost, which has great potential in the detection of pulse, heart rate, sound vibration and other tiny pressure.

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High-Sensitivity Flexible Pressure Sensor-Based 3D CNTs Sponge for Human–Computer Interaction

Polymers ◽

10.3390/polym13203465 ◽

2021 ◽

Vol 13 (20) ◽

pp. 3465

Author(s):

Jianli Cui ◽

Xueli Nan ◽

Guirong Shao ◽

Huixia Sun

Keyword(s):

Pressure Sensor ◽

High Performance ◽

Large Scale ◽

Low Cost ◽

Pressure Sensors ◽

Chemical Vapor ◽

High Sensitivity ◽

Wearable Electronics ◽

Wide Range ◽

Flexible Pressure Sensors

Researchers are showing an increasing interest in high-performance flexible pressure sensors owing to their potential uses in wearable electronics, bionic skin, and human–machine interactions, etc. However, the vast majority of these flexible pressure sensors require extensive nano-architectural design, which both complicates their manufacturing and is time-consuming. Thus, a low-cost technology which can be applied on a large scale is highly desirable for the manufacture of flexible pressure-sensitive materials that have a high sensitivity over a wide range of pressures. This work is based on the use of a three-dimensional elastic porous carbon nanotubes (CNTs) sponge as the conductive layer to fabricate a novel flexible piezoresistive sensor. The synthesis of a CNTs sponge was achieved by chemical vapor deposition, the basic underlying principle governing the sensing behavior of the CNTs sponge-based pressure sensor and was illustrated by employing in situ scanning electron microscopy. The CNTs sponge-based sensor has a quick response time of ~105 ms, a high sensitivity extending across a broad pressure range (less than 10 kPa for 809 kPa−1) and possesses an outstanding permanence over 4,000 cycles. Furthermore, a 16-pixel wireless sensor system was designed and a series of applications have been demonstrated. Its potential applications in the visualizing pressure distribution and an example of human–machine communication were also demonstrated.

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A capacitive sensor using resin thermoplastic elastomer and carbon fibers for monitoring pressure distribution

Pigment & Resin Technology ◽

10.1108/prt-10-2019-0098 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Guanzheng Wu ◽

Siming Li ◽

Jiayu Hu ◽

Manchen Dong ◽

Ke Dong ◽

...

Keyword(s):

Electrical Conductivity ◽

Carbon Fibers ◽

Pressure Sensor ◽

Pressure Sensors ◽

High Sensitivity ◽

Thermoplastic Elastomer ◽

Gauge Factor ◽

Capacitive Pressure Sensor ◽

Wearable Electronics ◽

Content Type

Purpose This paper aims to study the working principle of the capacitive pressure sensor and explore the distribution of pressure acting on the surface of the capacitor. Herein, a kind of high sensitivity capacitive pressure sensor was prepared by overlaying carbon fibers (CFs) on the surfaces of the thermoplastic elastomer (TPE), the TPE with high elasticity is a dielectric elastomer for the sensor and the CFs with excellent electrical conductivity were designed as the conductor. Design/methodology/approach Due to the excellent mechanical properties and electrical conductivity of CFs, it was designed as the conductor layer for the TPE/CFs capacitive pressure sensor via laminating CFs on the surfaces of the columnar TPE. Then, a ‘#' type structure of the capacitive pressure sensor was designed and fabricated. Findings The ‘#' type of capacitive pressure sensor of TPE/CFs composite was obtained in high sensitivity with a gauge factor of 2.77. Furthermore, the change of gauge factor values of the sensor under 10 per cent of applied strains was repeated for 1,000 cycles, indicating its outstanding sensing stability. Moreover, the ‘#' type capacitive pressure sensor of TPE/CFs was consisted of several capacitor arrays via laminating CFs, which could detect the distribution of pressure. Research limitations/implications The TPE/CFs capacitive pressure sensor was easily fabricated with high sensitivity and quick responsiveness, which is desirably applied in wearable electronics, robots, medical devices, etc. Originality/value The outcome of this study will help to fabricate capacitive pressure sensors with high sensitivity and outstanding sensing stability.

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Micro structuring polydimethylsiloxane elastomer film with 3D printed mold for low cost and high sensitivity flexible capacitive pressure sensor

2017 IEEE Electron Devices Technology and Manufacturing Conference (EDTM) ◽

10.1109/edtm.2017.7947545 ◽

2017 ◽

Cited By ~ 4

Author(s):

Bengang Zhuo ◽

Sujie Chen ◽

Xiaojun Guo

Keyword(s):

Pressure Sensor ◽

Low Cost ◽

High Sensitivity ◽

Capacitive Pressure Sensor ◽

3D Printed ◽

Polydimethylsiloxane Elastomer ◽

Micro Structuring

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Flexible Capacitive Pressure Sensors with Micro-Patterned Porous Dielectric Layer for Wearable Electronics

Journal of Micromechanics and Microengineering ◽

10.1088/1361-6439/ac49a3 ◽

2022 ◽

Author(s):

Jing Wang ◽

Longwei Li ◽

Lanshuang Zhang ◽

Panpan Zhang ◽

Xiong Pu

Keyword(s):

Pressure Sensor ◽

Flexible Electronics ◽

Dielectric Layer ◽

Pressure Sensors ◽

High Sensitivity ◽

Capacitive Sensor ◽

Human Motion ◽

Capacitive Pressure Sensor ◽

Wearable Electronics ◽

Emulsified Water

Abstract Highly sensitive soft sensors play key roles in flexible electronics, which therefore have attracted much attention in recent years. Herein, we report a flexible capacitive pressure sensor with high sensitivity by using engineered micro-patterned porous polydimethylsiloxane (PDMS) dielectric layer through an environmental-friendly fabrication procedure. The porous structure is formed by evaporation of emulsified water droplets during PDMS curing process, while the micro-patterned structure is obtained via molding on sandpaper. Impressively, this structure renders the capacitive sensor with a high sensitivity up to 143.5 MPa-1 at the pressure range of 0.068~150 kPa and excellent anti-fatigue performance over 20,000 cycles. Meanwhile, the sensor can distinguish different motions of the same person or different people doing the same action. Our work illustrates the promising application prospects of this flexible pressure sensor for the security field or human motion monitoring area.

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Carbonized Cotton Fabric-Based Flexible Capacitive Pressure Sensor Using a Porous Dielectric Layer with Tilted Air Gaps

Sensors ◽

10.3390/s21113895 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3895

Author(s):

Yelin Ko ◽

Chi Cuong Vu ◽

Jooyong Kim

Keyword(s):

Cotton Fabric ◽

Pressure Sensor ◽

Low Cost ◽

Pressure Sensors ◽

Capacitive Pressure Sensor ◽

Wearable Electronics ◽

Detection Range ◽

Air Gaps ◽

Wide Range ◽

Knitted Structure

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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