Wearable and high-sensitivity sensor based on laser-induced carbonization of polyimide on photographic paper substrate

Simplifying manufacturing processes and reducing production costs are crucial for developing high-performance flexible sensors, especially for applications in wearable electronics and health monitoring. This study presents a straightforward, cost-effective method for fabricating a flexible, photographic paper-based sensor. A laserinduced carbonization (LIC) process is employed on polyimide (PI) tape affixed to the paper surface to create a high-sensitivity, fast-response, multi-parameter flexible sensor capable of detecting bending strain, pressure, and temperature. The corrugated carbon film produced by the LIC process serves as the functional sensing material, while interdigital electrodes are formed by brush-coating conductive silver paste on the paper surface. Electrode masks are created by laser etching the PI tape. The fabricated LIC Paper-Based Sensor demonstrates superior strain sensitivity (K approximate to 187.5) compared to commercial strain gauges, exhibits strong temperature response linearity (R2=0.97773), and shows ultra-short response/recovery times (480 ms/720 ms) to minor pressure changes, with reliable repeatability and stability. Additionally, the sensor's feasibility for limb movement detection, breathing monitoring, and touch sensing has been verified.