A Flexible Dual‐Mode Capacitive Sensor for Highly Sensitive Touchless and Tactile Sensing in Human‐Machine Interactions

Abstract Human‐machine interaction(HMI) is extensively employed in various applications such as robotic control and augmented reality/virtual reality. However, HMIs are mainly based on single‐interaction mode, requiring bulky equipment to be worn or sustaining physical contact with the interfaces, resulting in limited interaction efficiency and intelligence. Here, it proposes a novel flexible dual‐mode capacitive sensor using 12 sensing units for touchless and tactile sensing during HMIs, the sensor has a labyrinth‐patterned electrode to improve the performance of proximity sensing and a truncated pyramid‐shaped porous hierarchical dielectric structure to improve the pressure sensing performance. The fabricated dual‐mode sensor is characterized by a high proximity detection range of up to 110 mm, the pressure detection range is from 0 to 200 kPa with a sensitivity of 0.464% kPa⁻¹. Further, the dual‐mode sensor exhibits excellent discrimination between proximity and pressure signals, along with remarkable stability and repeatability. Then, a touchless‐tactile HMI platform is developed for real‐time control of robotics through accurate perception of touchless hand gestures and contact‐pressing interactions. This platform demonstrates the superior dual‐mode sensing performance of the sensor and validates its potential in future intelligent HMI scenarios.