PVA Buffer Layer-Reinforced TPU @ MXene Fiber Strain Sensor for High-Sensitivity, Wide-Range Human Motion Detection

Crack-structured flexible strain sensors have attracted considerable interest in the field of flexible electronics due to their notable sensitivity and stretchability. However, crack propagation in these sensors restricts the strain range and compromises compatibility by collapsing the conductive network and degrading the interfacial adhesion. This research proposes a PVA optimization strategy based on the layer-by-layer assembly method, leading to the development of a PVA buffer layer-reinforced TPU @ MXene (MPTPU) fiber strain sensor. The incorporation of the PVA buffer layer improves interfacial adhesion and effectively alleviates stress concentration, thus broadening the effective sensing range of MPTPU. Additionally, hydrogen bonding within MPTPU improves the uniformity and adhesion of the conductive coating, enhancing the interfacial compatibility. The carefully engineered multilayer composite structure significantly boosts the sensor's performance and stability, exhibiting a sensitivity of 12.8, 50% stretchability, a detection threshold of 0.1%, and durability exceeding 10,000 stretching cycles. Furthermore, MPTPU demonstrates effective bending sensing performance and washability, making it well-suited for integration into textiles. The strain sensor accurately detects a wide range of human motions. With these advantages, such sensors hold great promise for applications in motion detection, health management, and wearable smart devices.