Naturally-Derived Wearable Strain Sensors with Enhanced Mechanical Properties and High Sensitivity.

Flexible strain sensors are of great interest for future applications in next-generation wearable electronic devices. However, most of the existing flexible sensors are based on synthetic polymer materials with limitations in biocompatibility and biodegradability, which may lead to potential environmental pollution. Here, we propose a naturally-derived wearable strain sensor based on natural-sourced materials including milk protein fabric, natural rubber, tannic and vitamin C. The obtained sensors exhibit a remarkably enhanced mechanical properties and high sensitivity contrast to currently reported natural resource-based sensors owing to the metal-ligand interface design and the construction of an organized three-dimensional conductive network, which well fit the requirements of electronic skin. This work represents an important advance toward the fabrication of naturally-derived high performance strain sensors and expanding possibilities in the design of environmental-friendly soft actuators, artificial muscle and other wearable electronic devices.