Self-Healable, Superhydrophobic, and Flexible Strain Sensor Based on Polyurethane Composite for Underwater Sensing

As one of the most important wearabledevices, flexiblesensorshave attracted the attention of researchers because they can be installedonto the skin of a human to monitor their movement, and they havethe advantages of excellent flexibility and comfort. However, mostof the devices cannot be used in an underwater environment, and theymay be destroyed by mechanical forces in harsh working conditions.There are many approaches to solve these issues, but unfortunately,less research has been carried out to solve them simultaneously. Toovercome these challenges, this research proposes a method for developinga sensor integrating superhydrophobicity and self-healing ability.The experimental results demonstrated that the sensor exhibited excellentperformance with a water contact angle of 153.6 & DEG;, a gauge factorof 145, and more than 10 000 cycle stability. In addition,it could self-heal at 50 & DEG;C after scratch, and the self-healingefficiency was 85.6%. It was capable of monitoring various movements,such as coughing, speaking, the bending and stretching of knees, elbows,and fingers. Furthermore, this device can be employed to monitor thehuman movement of swimming, and it can also realize underwater vibrationand impact of tiny droplets. This work provides a valuable designstrategy for electrical devices that can be widely applied in variousfields.