Open AccessPiezoresistive textile layer and distributed electrode structure for soft whole-body tactile skin
Author(s) -
Hyosang Lee,
Kyungseo Park,
Jung Kim,
Katherine J. Kuchenbecker
Publication year - 2021
Publication title -
smart materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.898
H-Index - 154
eISSN - 1361-665X
pISSN - 0964-1726
DOI - 10.1088/1361-665x/ac0c2e
Subject(s) - tactile sensor , piezoresistive effect , electrode , calibration , materials science , sensitivity (control systems) , fabrication , electrode array , acoustics , computer science , optoelectronics , electronic engineering , artificial intelligence , engineering , robot , medicine , chemistry , statistics , mathematics , alternative medicine , pathology , physics
Tactile sensors based on electrical resistance tomography (ERT) provide pressure sensing over a large area using only a few electrodes, which is a promising property for robotic tactile skin. Most ERT-based tactile sensors employ electrodes only on the sensor’s edge to avoid undesirable artifacts caused by electrode contact. The distribution of these electrodes is critical, as electrode location largely determines the sensitive regions, but only a few studies have positioned electrodes in the sensor’s central region to improve the sensitivity. Establishing the use of internal electrodes on a stretchable textile needs further investigation into piezoresistive structure fabrication, measurement strategy, and calibration. This article presents a comprehensive study of an ERT-based tactile sensor with distributed electrodes. We describe key fabrication details of a layered textile-based piezoresistive structure, an iterative method for choosing the current injection pathways that yields pairwise optimal patterns, and a calibration process to account for the spatially varying sensitivity of such sensors. We demonstrate two sample sensors with electrodes located only on the boundary or distributed across the surface, and we evaluate their performance via three methods widely used to test tactile sensing in biological systems: single-point localization, two-point discrimination, and contact force estimation.