Capillary bridge-assembled SBS elastomer microdot arrays for stress and strain sensing

High-sensitivity, high-precision, and long-life micro tactile sensors hold vast application prospects in fields such as health monitoring and intelligent robotics. However, current technologies typically confine microstructures within a single substrate material, which significantly restricts the application of micro-structured devices and machines across different scenarios. Herein, we have devised a capillary liquid bridge-induced self-assembly method that not only facilitates the miniaturization of tactile sensors but also enables the application of our fabricated micro sensing devices in diverse scenarios. We spatially confined and assembled the styrene-butadiene-styrene block copolymer (SBS) thermoplastic elastomer and aggregation-induced emission (AIE) molecules into a microdot array, and successfully fabricating a microscale tactile fluorescent sensor composed of SBS/AIE dot array. Sensors based on substrates with different stress properties can achieve detection of stress and strain in various application scenarios. Utilizing the fluorescence characteristics of AIE molecules, the sensor demonstrates a favorable response to both pressure and tensile forces. Notably, in conjunction with a convolutional neural network (CNN) simulation algorithm, the SBS/AIE molecular arrays sensors have realized the classification and regression of different pressures. This method of fabricating micron-scale arrays provides a novel and effective pathway for constructing micro tactile sensors suitable for different application scenarios.