Femtosecond laser micro-fabricated flexible sensor arrays for simultaneous mechanical and thermal stimuli detection

Abstract

Flexible sensor matrix with functionalities for multiple stimuli detection has prospect applications in structural health monitoring, internet of things, soft robotics, etc. However, fabrication of the sensor matrix in a simple, highly efficient, and scalable manner is still a challenge. To address this, a femtosecond (fs) laser micro-fabrication method is developed to fabricate a sensor matrix integrated with temperature and pressure sensor arrays. Through the programmable control of laser irradiation manner including scanning velocity, laser power, and laser irradiation intervals, the temperature and pressure sensor arrays were fabricated by the fs laser. The temperature sensors have a temperature coefficient of resistance of −0.52%/°C, higher than commercial temperature sensor based on platinum. The pressure sensors deliver a sensitivity of −2.01 kPa−1, a response speed of 0.030 s, a detection window from 0.001 to 80 kPa, and high mechanical stability. When the fs laser micro-fabricated pressure and temperature sensor arrays are integrated together, the sensor matrix could simultaneously detect external mechanical and thermal stimuli.