Highly Elastic and Fatigue-Resistant Graphene-Wrapped Lamellar Wood Sponges for High-Performance Piezoresistive Sensors

Abstract

Three-dimensional (3D) conductive aerogels with structural robustness and mechanical resilience are highly attractive for sensitive and stable pressure sensing. However, the fabrication of such 3D aerogels often relies on complicated bottom-up assembly processes that involve costly raw materials or intensive energy consumption or directly coating synthetic polymer sponges (e.g., polyurethane) with conductive materials, which may pose environmental concerns for their disposal. Herein, a simple and sustainable strategy is proposed to fabricate a reduced graphene oxide-coated wood sponge (RGO@WS) with a lamellar structure for high-performance piezoresistive sensors. The introduced RGO nanosheets endow the RGO@WS not only with high conductivity but also with high elasticity and excellent fatigue resistance. These features make it an ideal piezoresistive sensor with a high sensitivity of 0.32 kPa–1 (superior to most polymeric sponge-based sensors), high working stability over 10 000 cycles, and excellent sensing reproducibility at ultralow temperatures. Thanks to its prominent sensing performance, the RGO@WS-based sensor can serve as a wearable device for detecting human motions and physiological signals and allows for spatially resolved pressure mapping via integrating the sensors into a large-area sensing array. The developed highly elastic and fatigue-resistant RGO@WS represents a promising and sustainable alternative to the synthetic polymer-based piezoresistive sensors.

Mechanically Robust and Elastic Graphene/Aramid Nanofiber/Polyaniline Nanotube Aerogels for Pressure Sensors

“…In a stress range of 40 Pa to 0.7 kPa, the S is also calculated as high as 1.73 kPa −1 , as shown in the inset image. The S value is higher than that for reported carbon aerogels sensors, 8,9,25,56,57 such as PANI/BC/CH aerogel (1.41 kPa −1 ), 56 rGO/PI aerogel (0.18 kPa −1 ), 25 CNFAs aerogel (1.02 kPa −1 ), 8 and Zn 2 GeO 4 @polypyrrole aerogel (0.38 kPa −1 ). 9 In relatively high pressure range (0.7 kPa < P < 7 kPa), the S value is 0.3 kPa.…”

Recent Advances in Flexible Sensors and Their Applications

“…This allowed the sensor to measure precise human motions such as coughing and breathing [61]. Other porous materials such as 3D Grapheme are also used for making piezoresistive sensors [62][63][64][65]. A list of gauge factor GF values for several materials can be found in Table 1.…”

Ultralight, Elastic, Hybrid Aerogel for Flexible/Wearable Piezoresistive Sensor and Solid–Solid/Gas–Solid Coupled Triboelectric Nanogenerator

“…The unique 3D porous structures of aerogels provide high porosity, ultralow density, and high specific surface area. [ 15 , 16 , 17 ] Conductive, compressible, and elastic aerogels have been considered as excellent candidates for fabricating flexible/wearable devices [ 18 , 19 , 20 , 21 ] such as piezoresistive sensors, [ 15 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] and energy harvesting devices. [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ] The flexible and compress 3D porous structure of aerogels can provide large numbers of adjustable contact areas which can modulate the electrical resistance under the external pressure.…”