Facile fabrication of highly durable superhydrophobic strain sensors for subtle human motion detection

Endowing strain sensors with superhydrophobicity is of great importance to guarantee their long-term service under harsh environments (such as wet, acid, alkali and salt atmospheres), whereas, the development of superhydrophobic strain sensors remains a great challenge. Herein, we realized a superhydrophobic and highly sensitive sensor for subtle human motion detection by designing a superhydrophobic and electrically conductive coating on cotton textile, via a facile drop-coating method. The resultant strain sensor showed a large water contact angle of 161.3° and a low sliding angle of 3.8° The superhydrophobic characteristics can keep almost unchanged even after undergoing 1000 peeling cycles, 1000 stretching-release cycles, and 1000 bending-releasing cycles, revealing its excellent mechanical robustness. High sensitivity with the maximum gage factor of 169 was achieved for the strain sensor under a small strain of 0–10%, and the sensing performance also showed well durability. Moreover, our sensor can effectively detect various subtle human physiological signals and body motions even under harsh conditions. These admirable features make the sensor promising applications in wearable electronics, personalized health monitoring, sound recognition, and so on.