A hierarchically patterned, bioinspired e-skin able to detect the direction of applied pressure for robotics

TLDR

Tactile sensing is essential for dexterous robotic manipulation, particularly the real‑time measurement of normal and shear forces needed for slip detection and handling fragile objects. The study introduces a biomimetic soft electronic skin that can measure and discriminate normal and tangential forces in real time. It achieves this through a three‑dimensional structure mimicking the interlocked dermis‑epidermis interface, comprising an array of capacitors that sense forces. The e‑skin delivers high sensitivity, minimal hysteresis, excellent cycling stability, millisecond response times, and successfully guided a robot arm in multiple tasks, highlighting its applicability in robotic tactile feedback.

Abstract

Tactile sensing is required for the dexterous manipulation of objects in robotic applications. In particular, the ability to measure and distinguish in real time normal and shear forces is crucial for slip detection and interaction with fragile objects. Here, we report a biomimetic soft electronic skin (e-skin) that is composed of an array of capacitors and capable of measuring and discriminating in real time both normal and tangential forces. It is enabled by a three-dimensional structure that mimics the interlocked dermis-epidermis interface in human skin. Moreover, pyramid microstructures arranged along nature-inspired phyllotaxis spirals resulted in an e-skin with increased sensitivity, minimal hysteresis, excellent cycling stability, and response time in the millisecond range. The e-skin provided sensing feedback for controlling a robot arm in various tasks, illustrating its potential application in robotics with tactile feedback.