Bionic tactile sensor based on starfish tube foot structure

Artificial tactile perception sensors have great application value in robotics, medical health, intelligent prosthetics, and human-computer interaction. However, existing sensors encounter difficulties in achieving high sensitivity, good linear response, and high spatial resolution, which has become a key problem restricting their practical application. Here, inspired by the tube foot system in starfish, we report the design, fabrication, and performance of a multi-level dome structure tactile sensor (MLDSTS) that provides simultaneous high sensitivity, excellent linearity, stability, and high resolution. Through a series of experiments, a comprehensive and systematic characterization and analysis of its sensing performance were conducted. The experimental results showed that the constructed multi-level dome array structure could effectively expand the linear detection range of the sensor while stably maintaining high spatial resolution. Its linear range was increased by about 2 times compared with the single-level dome structure, and realized segmented sensitive response. The sensor could detect weak external forces as low as 0.1 N, with a sensitivity of 1.309 V/N in the range of 0.1-3 N and 0.447 V/N in the range of 4-10 N, possessing both high precision and large-range detection capabilities. Through tests in various practical application scenarios such as respiration monitoring, water droplet detection, fabric texture recognition, and knuckle movement monitoring, it was confirmed that the sensor exhibited excellent stability and detection accuracy in different pressure scenarios, and its performance was significantly superior to that of single-dome structure sensors. The research results indicated that the multi-level dome structure provided an effective strategy to solve the industry problem that it was difficult to balance the sensitivity, linearity, and resolution of tactile sensors. With its comprehensively excellent performance, the MLDSTS sensor has broad application prospects in the fields of flexible electronics, intelligent health monitoring, human-computer interaction, and intelligent robots.