Laser-Textured Polydimethylsiloxane/Multiwalled Carbon Nanotubes Composites for Strain Sensors Resistant to Droplet Interference

Flexible wearable sensors are widely used in various fields with the development of technology. However, it is necessary to consider the interference they may be subjected to in environments such as rainy and humid conditions in practical applications. Superhydrophobic surfaces can effectively improve the stability of flexible sensors in harsh environments. In this study, a method is proposed to achieve the desired superhydrophobic properties for anti-droplet interference by surface processing of Polydimethylsiloxane/multiwalled carbon nanotubes (PDMS/MWCNT) composites using a simple and cost-effective nanosecond laser. Through laser processing of the surface, abundant rough structures are obtained, which subsequently alters the wettability of the PDMS/MWCNT surface. The contact angle of the laser-etched PDMS/MWCNT surface can reach up to approximate to 157 degrees, and the rolling-off angle drops to approximate to 3 degrees, showing excellent superhydrophobic properties. The stability of the prepared superhydrophobic PDMS/MWCNT composites under droplet interference is further studied. The results show that the prepared superhydrophobic surface can make PDMS/MWCNTs well isolated from droplet interference and has excellent corrosion resistance. In addition, the prepared PDMS/MWCNT composite shows good sensitivity (GF = 7.92) and can well detect human motion signals. The research results provide a strategy for improving the reliability and stability of strain sensors in harsh environments.