Highly Flexible and Sensitive Proximity Sensor Based on Liquid Metal Microfluidic Fibers

In recent years, the study of proximity sensors has garnered significant attention, and the introduction of flexible proximity sensors is expected to markedly enhance the naturalness of human-machine interaction and user experience. This paper presents the design and performance analysis of a highly flexible capacitive proximity sensor. The sensor employs highly flexible liquid metal microfluidic fibers to construct a double-helix structure, significantly enhancing its sensitivity (0.062pF/mm, d<30mm) and spatial efficiency. The use of commercial silicone tubes makes the manufacturing process easier to implement, more cost-effective, and with higher success rates. Through mathematical model analysis and simulation modeling, the working principles and electric field distribution characteristics of the sensor are discussed in detail, verifying its feasibility and high sensitivity potential in proximity sensing. Experimental results demonstrate the sensor's excellent performance in proximity sensing and dynamic response, as well as outstanding capacitive hysteresis (1.8%) and repeatability (>200 times). Finally, the application prospects of the sensor in intelligent control systems are validated through robotic arm control experiments.