Liquid Metal-Based Flexible and Wearable Sensor for Functional Human–Machine Interface

Abstract

Rigid sensors are a mature type of sensor, but their poor deformation and flexibility limit their application range. The appearance and development of flexible sensors provide an opportunity to solve this problem. In this paper, a resistive flexible sensor utilizes gallium−based liquid metal (eutectic gallium indium alloy, EGaIn) and poly(dimethylsiloxane) (PDMS) and is fabricated using an injecting thin−line patterning technique based on soft lithography. Combining the scalable fabrication process and unique wire−shaped liquid metal design enables sensitive multifunctional measurement under stretching and bending loads. Furthermore, the flexible sensor is combined with the glove to demonstrate the application of the wearable sensor glove in the detection of finger joint angle and gesture control, which offers the ability of integration and multifunctional sensing of all−soft wearable physical microsystems for human–machine interfaces. It shows its application potential in medical rehabilitation, intelligent control, and so on.

Direct mask printing of highly stretchable liquid metal electrodes for strain sensors

“…For one thing, using liquid metal as a conductor and combining flexible circuits with traditional electronic chips can be used to prepare wearable electronic devices, such as various physiological electrical signal detection circuits [15]- [17]. For another, the combination of liquid metal and robots can be used for human-machine interaction, robot sensors, and other devices [18], [19].…”

Wearable Piezoelectric Sensors Based on BaTiO3 Films for Sarcopenia Recognition

“…In addition, piezoelectric sensors are self-powered, exhibit reduced system complexity, and can operate over a wide temperature range. [20][21][22][23][24] Strain sensors and triboelectric sensors are usually used for motion monitoring, but strain sensors usually require additional power supply [25] and triboelectric sensors can exhibit nonlinearity. [26] In previous studies, surface electromyography and inertial acceleration sensors were often used to recognizing sarcopenia by measuring surface electromyography signals and gait parameters, respectively.…”