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. The flexible piezoresistive tactile sensor (FPTS) preparation process. (a) Preparation of multiwalled carbon nanotubes (MWCNTs) solution. (b) Preparation of polydimethylsiloxane (PDMS) solution. (c) Schematic of high pressure spray of MWCNTs solution on the mold and then PDMS was spin-coated on the mold. (d) After drying the mold, the MWCNTs/PDMS composite membrane was cut and packaged to fabricate a FPTS. image