Scalable tactile sensor arrays on flexible substrates with high spatiotemporal resolution enabling slip and grip for closed-loop robotics

Sci Adv. 2020 Nov 13;6(46):eabd7795. doi: 10.1126/sciadv.abd7795. Print 2020 Nov.

Abstract

We report large-scale and multiplexed tactile sensors with submillimeter-scale shear sensation and autonomous and real-time closed-loop grip adjustment. We leveraged dual-gate piezoelectric zinc oxide (ZnO) thin-film transistors (TFTs) fabricated on flexible substrates to record normal and shear forces with high sensitivity over a broad range of forces. An individual ZnO TFT can intrinsically sense, amplify, and multiplex force signals, allowing ease of scalability for multiplexing from hundreds of elements with 100-μm spatial and sub-10-ms temporal resolutions. Notably, exclusive feedback from the tactile sensor array enabled rapid adjustment of grip force to slip, enabling the direct autonomous robotic tactile perception with a single modality. For biomedical and implantable device applications, pulse sensing and underwater flow detection were demonstrated. This robust technology, with its reproducible and reliable performance, can be immediately translated for use in industrial and surgical robotics, neuroprosthetics, implantables, and beyond.