Liquid-Metal-Painted Stretchable Capacitor Sensors for Wearable Healthcare Electronics

Flexible biosensors have become increasingly important in a variety of emerging healthcare applications. Many efforts have been made to obtain stretchable and highly conductive biomaterials, most of which are based on gold or silver nanoparticles. However, such materials have a number of disadvantages. This study proposes flexible capacitor sensors based on 3M VHB 4905 tape and GaInSn and designs a wearable biosensor monitoring device that uses the CAV444 chip. The system exhibits highly linear response to stretching, rotation, and pressure. The practical applications of these sensors are explored, such as measuring the motion angle of the wrist and finger joint and responses to pressure. The proposed flexible capacitor sensors have many potential biomedical applications, such as parameter measurement, accident alert, electronic skin, motion feedback, and remote control.