In Situ Co‐transformation of Reduced Graphene Oxide Embedded in Laser‐Induced Graphene and Full‐Range On‐Body Strain Sensor

Abstract

On‐body strain information provides various indicators such as heart rate, physiological pulse, voice waveform, respiratory rate, and body motion status. Recent advances in wearable strain sensors using nanomaterials have significantly enhanced sensor performance with regard to sensitivity, detectable range, and response time. However, it is still challenging to obtain all types of body strain information, from small vibrations to joint movements, using one type of sensor. Herein, a full‐range on‐body strain (FROS) sensor covering ultrasmall‐to‐large strains such as vocal vibration and joint movement is reported. To achieve an ultrawide detectable range, reduced graphene oxide (rGO)‐embedded laser‐induced graphene (LIG) is synthesized by laser engraving on a graphene oxide (GO)‐embedded polyimide (PI) complex film. An rGO‐LIG homostructure based on sp2‐carbons is photothermally reconstructed from the GO‐PI heterostructure in a complex film by in situ co‐transformation and then transferred to an elastomer substrate. The fabricated FROS sensor successfully performs on‐body strain monitoring of various indicators, such as physiological pulse, vocal sound waveform, and body movement, as well as American sign language translation. Furthermore, it is believed that this rGO‐LIG homostructure‐based material synthesized by in situ co‐transformation can potentially provide novel functionalities in fields such as wearable electronics, humanoid, soft robotics, and intelligent prosthetics.

High‐performance piezoresistive sensors based on transfer‐free large‐area PdSe2 films for human motion and health care monitoring

“…Additionally, the sensor can be attached to the finger joint to monitor the different gestures from ~180° to 135° (Figure 4B). The sensor exhibits consistent resistive changes with different bending angles, promising for finger gesture recognition 40 . When attached to the throat, the sensor can track vocal cord vibrations (Figure 4C).…”

A soft robot tactile fingertip for grasping surface posture detection

“…It should have good conductivity and elasticity. Some methods of preparing conductive elastic porous materials based on carbon nanotubes [29], graphene [30], Mxene [31] and other nano-conductive materials have been proposed in literature. However, considering the requirements of high conductivity, electrical stability and low cost, the commercial nickel-plated polyurethane conductive sponge is chosen as the elastic porous electrode material for the soft robot tactile fingertip.…”

High-Fidelity, Low-Hysteresis Bionic Flexible Strain Sensors for Soft Machines

“…Whereas some intrinsic limitations of conductive elastomers would critically impair the output signal quality of the sensors. One is the fidelity when monitoring dynamic strain. ,, Signal distortion arises regularly due to the dynamic competition between longitudinal and transverse conductive paths in conductive elastomers during stretching. Currently, these overshoot responses of resistance signals are highly reliant on subsequent processing and correction, whereas existing algorithms have significant data dependencies and are incapable of explaining the decisions made.…”