Multifunctional fiber-shaped flexible wearable strain sensor with high sensitivity and wide sensing range for detecting autonomous driving technology in automobiles

Abstract

Flexible strain sensors have developed rapidly and shown enormous application prospects in human motion detection, intelligent robots, and other fields in recent years. However, developing satisfactory strain sensors that meet the requirements of high sensitivity, wide detection range and prominent durability remains a significant challenge. Herein, we developed a flexible and wearable multifunctional fiber-shaped carbon black (CB) and thermoplastic polyurethane (TPU) strain sensor (defined as CTSS) by combining wet spinning and ultrasound. The CTSS possesses characteristics of lightweight, wide sensing range (>390 %), high sensitivity (up to 1414), short response and recovery time (200 ms), ultralow detection limit (0.005 % strain) and good durability. These advantages endow the CTSS with good capability to monitor complicated human activities efficiently (e.g., joint bending, facial expression and breathing). CTSS can also clearly distinguish different bending states. It was then used to monitor the steering of a car in real-time, proving its tremendous potential as high performance flexible electronics device. CTSS is then encapsulated with Ecoflex (E-CTSS) as a single packaged fiber, exhibiting good triboelectric nanogenerator (TENG) performance, with a maximum output voltage beyond 12V for a single packaged fiber, and can maintain stable output. Indicating that E-CTSS has self powered sensing capability.