A Flexible Pressure Sensor Based on Magnetron Sputtered MoS(2)

Although two-dimensional (2D) layered molybdenum disulfide (MoS(2)) has widespread electrical applications in catalysis, energy storage, and photodetection, there are few reports available regarding sputtered MoS(2) for piezoresistive sensors. In this research, we found that the resistance of magnetron sputtered MoS(2) on a flexible substrate changed significantly and regularly when pressure was applied. Scanning electron microscope (SEM) and atomic force microscope (AFM) images revealed an MoS(2) micro-grain-like structure comprising nano-scale particles with grooves between the particles. Chemical characterization data confirmed the successful growth of amorphous MoS(2) on a polydimethylsiloxane (PDMS) substrate. A micro-thickness film flexible sensor was designed and fabricated. In particular, the sensor with a 1.5 μm thick polydimethylsiloxane (PDMS) substrate exhibited the best resistance performance, displaying a maximum ΔR/R of 70.39 with a piezoresistive coefficient as high as 866.89 MPa(−1) while the pressure was 0.46 MPa. A proposed flexible pressure sensor based on an MoS(2) film was also successfully used as a wearable pressure sensor to measure plantar pressure and demonstrated good repeatability. The results showed that the thin film pressure sensor had good piezoresistive performance and high sensitivity.