A Flexible Bending Sensor Based on C-Shaped FBG Array for Curvature and Gesture Recognition

Abstract

Human joints enable precise bending for fine manipulation and complex movements. Similarly, robotic flexibility relies on bending structures, where accurate bending perception is crucial for precise control and enhanced humanrobot interaction. This paper proposes a C-shaped fiber optic array, embedding a fiber Bragg Grating sensor array into a 2 mm thick silicone layer, successfully achieving a highly sensitive (300 pm/N) and electromagnetic interference-resistant bending sensor. The flexible sensor can sensitively detect external stimuli, such as the touch of a 1g weight or a feather, and exhibits a good linear relationship with curvature, facilitating accurate curvature classification. Additionally, leveraging the wearable nature of the sensor, we achieved the detection of finger bending angles. Finally, by attaching the sensor to the wrist and combining it with deep learning algorithms, we achieved 100% gesture recognition accuracy. This sensor holds significant potential for applications in fields such as fruit size classification, rehabilitation healthcare, and human-robot interaction.