Ultra-Robust and Sensitive Flexible Strain Sensor for Real-Time and Wearable Sign Language Translation

Flexible strain sensors with high sensitivity and high mechanical robustness are highly desirable for their accurate and long-term reliable service in wearable human-machine interfaces. However, the current application of flexible strain sensors has to face a trade-off between high sensitivity and high mechanical robustness. The most representative examples are micro/nano crack-based sensors and serpentine meander-based sensors. The former one typically shows high sensitivity but limited robustness, while the latter is on the contrary. Herein, ultra-robust and sensitive flexible strain sensors are developed by crack-like pathway customization and ingenious modulation of low/high-resistance regions on a serpentine meander structure. The sensors show high cyclic stability (10 000 cycles), strong tolerance to harsh environments, high gauge factor (>1000) comparable with that of the crack-based sensor, and fast response time (<58 ms). Finally, the sensors are integrated into a wearable sign language translation system, which is wireless, low-cost, and lightweight. Recognition rates of over 98% are demonstrated for the translation of 21 sign languages with the assistance of machine learning. This system facilitates achieving barrier-free communication between signers and nonsigners and offers broad application prospects in gesture interaction.