Skin-Inspired, High-Resolution, Intelligent Aerosol Jet 3D-Printed Palmtop with Multisensory Integration

Abstract

Electronic skin (E-skin) with multimodal sensing demonstrates significant capability in acquiring object characteristics grasped by robotic artifacts. As the spatial resolution of the sensing nodes increases on the E-skin, it introduces challenges related to compact design and wiring. Herein, the design, fabrication, and characterization of an ultrathin, ultralow cost, highly compact, and flexible multimodal sensing hierarchical palmtop with 390 piezoresistive tactile pressure sensing nodes and 5 capacitive hydration sensing nodes are presented. Each tactile pressure sensing node consists of two 3D-printed Ag nanoparticle ink electrodes sandwiching a piezoresistive film. The hydration sensing nodes in contrast are capacitive type with 3D-printed Archimedean spiral Ag nanoparticle ink electrodes. Upon characterization, the pressure sensors exhibit a sensitivity of 1.188 kPa⁻¹ and an impressive sensing range from 10 to 600 kPa. Meanwhile, the hydration sensing nodes display a sensitivity of 3.124 per percentage increase in hydration level, with a hydration sensing range of 25%–75%. Subsequently, machine learning is used to discriminate the region touched on the palmtop, object shapes, and hydration levels. Given its multifaceted capabilities, this palmtop is poised to find potential applications in various robotic contexts such as robotic hands, rehabilitation hand exoskeletons, and in the sphere of augmented reality.