Research on a flexible optical tactile sensor based on a liquid lens structure

Based on the liquid lens focus mechanism, the optical tactile sensor and its signal acquisition system are designed. To balance the relationship the manufacturing complexity, perceptual precision and sensitivity, perceptual stability, and robustness of the tactile sensor, they are important components of smart devices. Some of them, such as robots, smart wearable devices, etc., because they can intuitively reflect the interaction state of the man-machine-environment. Firstly, according to the liquid-film lens structure, the sensing structure of the optical tactile sensor was designed, and its tactile perception mechanism was explored; secondly, the signal acquisition system for the sensor was designed to improve the integration of the tactile sensing system; finally, the optical tactile sensor performance test and application demonstration platform was designed-built to test-calibrate the sensor system performance, and explore its application potential in touch force detection. Experiments show that the sensor has an effective range from 0.01 to 1.2 N, a sensitivity of up to 0.1654 V/N (range from 0.01 to 0.4 N), and a linear goodness of fit of up to R2 = 0.996 (range from 0.01 to 0.4 N). Good perceptual stability and responsiveness (loading response time: 0.078 s), can achieve accurate measurement of the target mass, with an error of less than 0.02 N.