Highly stretchable, superhydrophobic and wearable strain sensors based on the laser-irradiated PDMS/CNT composite

In this paper, we adopted a rapid and facile method of fabricating highly stretchable, superhydrophobic and wearable strain sensors via laser texturing with an inexpensive CO2 laser engraver. Carbon nanotube (CNT) is uniformly dispersed in a polydimethylsiloxane (PDMS) matrix to construct a stable conductive network. After the PDMS/CNT composite was irradiated with the laser, the surface of the composite became considerably rough, forming irregular convex structures that contributed to the superhydrophobic surface. The laser-irradiated PDMS/CNT composite exhibited outstanding superhydrophobicity (water contact angle of 155° and sliding angle of 4.5°), superior anti-corrosion properties, good sensitivity (gauge factor of 3.1) and a wide sensing range (up to 100%). In addition, it displayed excellent durability and reproductivity over 5000 tension cycles even under 100% strain. Such strain sensors have potential applications in engineering and medical fields, including wearable electronics, electronic skins, human health monitoring and soft robots in harsh environments.