A flexible capacitive proximity-tactile dual-mode sensor based on the biomimetic petal-like electrode

Abstract

Flexible capacitive proximity-tactile dual-mode sensors not only have good stability, non-contact detection distance and sensitivity, but also can get rid of the limitation of single contact sensing performance. It integrates other functions such as extensibility, tactile perception, etc., forming dual-mode flexible wearable electronic skins with strong adaptability to application scenarios. However, under the premise of fully balancing the manufacturing process and cost, how to effectively and significantly improve the non-contact and contact performance of capacitive flexible proximity sensors remains an important issue. By utilizing the edge effect and biomimetic concept, we propose a flexible capacitive dual-mode sensor based on petal-like electrode, which has a relative variation of capacitance to −32.4 % and can detect objects within 5 cm. With the further assistance of the porous microstructure dielectric layer, the tactile performance of the sensor exhibits high sensitivity of 0.132 kPa⁻¹, low pressure resolution of 6.9 Pa, and good stability after thousands of pressure test cycles. In addition, an object detection system based on a flexible capacitive dual-mode sensor array has been developed. The experimental results show that the shape and position of the approaching object are detected in proximity mode, and the size and position distribution of pressure are detected in tactile mode. The ideal performance of sensor has broad application prospects in fields such as spatial recognition, human-computer interaction, and intelligent electronic skin.