Flexible optical tactile sensor based on a liquid-membrane lens structure

Based on the liquid lens focus mechanism, a novel, to the best of our knowledge, optical tactile sensor is designed by taking advantage of the structure simplicity, fast response, and environmental immunity. The design of the tactile sensing mechanism used the liquid-membrane lens structure. To integrate the tactile sensing system, we designed a data acquisition circuit unit. A performance test platform was built, and performance testing and two application demonstrations were conducted. The experiment’s result showed that the linear fitting degree was greater than 0.988, the load response time was 0.078 s, the target mass was accurately measured, the maximum error was less than 0.02 N, and the fine adjustment of the LED light intensity was achieved.