Lotus root structure-inspired Ti3C2-MXene-Based flexible and wearable strain sensor with ultra-high sensitivity and wide sensing range

Flexible sensors have wide-ranging application prospects in the field of human health motion monitoring. However, it is still a challenge to design and prepare strain sensors with both high sensitivity and wide operating range. Inspired by the fiber connection structure of lotus root, the carbon nanocoils (CNCs) with large aspect ratio (acting as the lotus root fibers) is used as a conductive bridge to connect the fragile Ti3C2-MXene nanosheet layers, significantly enhancing the sensing range of the sensor. Waterborne polyurethane (WPU) encapsulated strain sensor (Ti3C2/CNCs/WPU) can achieve GF values and sensing ranges of 474 and 220%, respectively. In addition, this sensor shows reliable responses at different frequencies and can withstand more than 1000 stretch-release cycles. More importantly, the composite strain sensor can accurately sense and monitor different limb movements and human body motion states, showing broad application prospects in real-time human health detection.