Structure and Wiring Optimized TT/MT Double-Helical Fiber Sensors: Fabrication and Applications in Human Motion Monitoring and Gesture Recognition.

A fibrous flexible sensor, with its small size, minimally burdens the human body, ranking among the most user-friendly flexible sensors. However, its application is often limited by damage caused by electrode movement, as flexible sensors are typically attached to joints, which can be greatly alleviated by placing the two electrodes on the same side. Inspired by the hydrogen bonds in the double-helical structure of DNA, the double-helical electrode design is commonly found and applied in fiber-based batteries and supercapacitors into fibrous flexible sensors through coaxial wet-spinning and further treatment. The double helical sensor exhibits high strength and maintains stable operation and is prepared under over 300% strain with gauge factors (GF) of 0.9, 39.5, and 349, respectively, in its working ranges. This unique single-sided electrode structure also enabled applications such as water flow sensing. The sensor into a smart glove capable of real-time is further integrated, five-channel finger motion detection, and used a convolutional neural network (CNN)-based machine learning algorithm to achieve 98.8% accuracy in recognizing six common gestures. This study provides a novel approach to optimize the electrode distribution in fiber-based flexible sensors through an internally encapsulated double-helical structure, making a significant contribution to the field of flexible sensing.