Laser-Induced Graphene-Based Flexible Strain Sensor for Human Finger Motion Detection

Wearable and flexible electronic devices are important in health monitoring systems. Laser-induced graphene (LIG) has gained popularity in flexible electronics due to its distinct physical and electrical properties. LIG can be formed by direct irradiation of the laser on polyimide (PI) film, resulting in a porous structure with high conductivity. In this study, resistive laser-induced graphene sensors of three different shapes with similar surface areas were engraved on the PI film. The response of resistive strain sensors was measured in terms of resistance by bending them at various angles ranging from 0 to 90 degrees. The performance of the three different sensors with the same surface area of 130 mm2 was compared and its reversibility and repeatability were investigated. The developed resistive LIG strain sensor provides a stable and fast response with high sensitivity.