Design and Development of a Flexible Optical Force Sensor for Robotic Applications

This paper presents the design, fabrication, and evaluation of a novel optical force sensor for soft robotic applications. The sensor utilizes a flexible structure that deforms under applied force, modulating the reflected light detected by a photo-detector array. The working principle of interpreting the force by measuring the displacement of the ceiling was first validated using simulation studies. Two prototypes were fabricated using both 3D-printed TPU and casting silicon to compare their hysteresis behavior, with silicon exhibiting superior performance. Furthermore, the influence of the light source's cone angle on sensor sensitivity was investigated, showing that a narrower angle enhances sensitivity. The findings highlight the sensor's scalability, cost-effective fabrication, and suitability for integration into force-controlled robotic grasping systems.