A Flexible Multimodal Sensor for Fully Decoupled Crosstalk-Free Pressure and Temperature Sensing via Laser Direct Writing

This paper presents a flexible multimodal all-in-one structure sensor for pressure and temperature sensing via an ultraviolet (UV) nanosecond laser. To achieve temperature sensing, we laser patterned the flexible thermoelectric generator with the graphene film. Then, we prepared Carbon Powder-Carbon Nanotube/Polydimethylsiloxane (CP-CNT/PDMS) conducting polymers based on the principle of piezoresistive effect, and then fabricated microcone structures using UV laser as pressure-sensing layers. Experimental results show that our sensor can distinguish pressure and temperature signals with only a single channel signal acquisition. Raman spectroscopy analysis shows that P-type doping of graphene films can be performed using FeCl3, and the power factor of thermoelectric generators is four times higher than that before doping. Finite element analysis (FEA) results show a microcone array with a height of 500 μm and a width of 100 μm exhibit optimized sensitivity (sensitivity of 0.587 kPa$^{-1}$) and detection range (range of 160 kPa)