Laser Direct Writing of Highly Crystalline Graphene on Polydimethylsiloxane for Fingertip‐Sized Piezoelectric Sensors
Shuichiro Hayashi, Fumiya Morosawa, Mitsuhiro Terakawa
Abstract
The patterning of electrically conductive structures directly onto the polydimethylsiloxane (PDMS) surface is crucial for the realization of flexible and elastic devices. Herein, defocused femtosecond laser pulses are irradiated for the fabrication of highly crystalline graphitic carbon structures on PDMS and a high electrical conductivity of ≈51.6 S m −1 is achieved. Utilizing the elasticity of PDMS and the high conductivity of fabricated structures, a fingertip‐sized pressure sensor, which can detect pressures as low as ≈0.1 Pa, is realized. Moreover, a novel ring‐shaped heart rate (HR) monitor, capable of measuring the HR from the index finger, is demonstrated, indicating the potential of fabricated structures in miniature and wearable healthcare applications.