Superhydrophobic wearable sensor: fabrication, application, and perspective

Wearable sensors have attracted considerable interest due to their ability to detect a variety of information generated by human physiological activities through physical and chemical means. The performance of wearable sensors is limited by their stability, and endowing wearable sensors with superhydrophobicity is one of the means to enable them to maintain excellent performance in harsh environments. This review emphasizes the imperative progress in flexible superhydrophobic sensors for wearable devices. Besides, the wettability principle and the mechanism of wearable sensors are briefly introduced to propose the combination of superhydrophobicity and wearable sensors. Next, superhydrophobic substrates for wearable sensors, including but not limited to, polydimethylsiloxane, polyurethane, gel, rubber, and fabric, are described in depth, and also the respective fabrication processes and performances. Moreover, the utility of superhydrophobic wearable sensors in a normal intelligent environment is described, highlighting their application in monitoring physiological signals, such as physical movement, pulse, vibration, temperature, perspiration, respiration, and so on. Finally, this review evaluates the challenges and dilemmas that wearable sensors must be overcome for further development and improve the functional performance of wearable sensors, paving the way for their expansion into advanced wearable sensing systems.