Research on multiwalled carbon nanotubes spray method for preparing flexible piezoresistive tactile sensor

Flexible piezoresistive tactile sensor (FPTS) is widely used in wearable devices, e-skin, and so on. However, the performance consistency and durability hinder its widespread application at a larger scale. It is still a challenge to prepare conductive composites with high performance consistency and high durability. In this research, a multiwalled carbon nanotubes (MWCNTs)/polydimethylsiloxane FPTS with high performance consistency and high durability was prepared by a combination of spray and spin coating method. The spray parameters of MWCNTs solution were optimized by numerical simulation, and a self-developed high pressure spray device was adopted to realize the high-pressure spray. In the 6000 tensile cycles experiments, the fluctuation of FPTS resistance is less than 5%. The range of prepared FPTS can reach 1.2 kPa, and the sensitivity is 0.8 kPa⁻¹. The results of mouse click and wrist bending tests confirmed that the prepared FPTS can satisfy the detection requirements of wearable devices.