Durable superhydrophobic surface in wearable sensors: From nature to application

The current generation of wearable sensors often experiences signal interference and external corrosion, leading to device degradation and failure. To address these challenges, the biomimetic superhydrophobic approach has been developed, which offers self-cleaning, low adhesion, corrosion resistance, anti-interference, and other properties. Such surfaces possess hierarchical nanostructures and low surface energy, resulting in a smaller contact area with the skin or external environment. Liquid droplets can even become suspended outside the flexible electronics, reducing the risk of pollution and signal interference, which contributes to the long-term stability of the device in complex environments. Additionally, the coupling of superhydrophobic surfaces and flexible electronics can potentially enhance the device performance due to their large specific surface area and low surface energy. However, the fragility of layered textures in various scenarios and the lack of standardized evaluation and testing methods limit the industrial production of superhydrophobic wearable sensors. This review provides an overview of recent research on superhydrophobic flexible wearable sensors, including the fabrication methodology, evaluation, and specific application targets. The processing, performance, and characteristics of superhydrophobic surfaces are discussed, as well as the working mechanisms and potential challenges of superhydrophobic flexible electronics. Moreover, evaluation strategies for application-oriented superhydrophobic surfaces are presented. This review provides a thorough overview of the latest advancements in the field of superhydrophobic flexible wearable sensors. The review encompasses a wide range of aspects including the manufacturing processes, evaluation methods, and specific applications of flexible sensors that have been functionalized with non-wetting behavior. Furthermore, the review summarizes the various working mechanisms of superhydrophobic and flexible devices, followed with a detailed discussion of the potential challenges that may arise during the real-world implementation. image