Haptic Intelligence Article 2021

Piezoresistive Textile Layer and Distributed Electrode Structure for Soft Whole-Body Tactile Skin

Sensor overview

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.

Author(s): Hyosang Lee and Kyungseo Park and Jung Kim and Katherine J. Kuchenbecker
Journal: Smart Materials and Structures
Volume: 30
Number (issue): 8
Pages: 085036
Year: 2021
Month: July
Project(s):
Bibtex Type: Article (article)
DOI: 10.1088/1361-665X/ac0c2e
State: Published
Electronic Archiving: grant_archive
Note: Hyosang Lee and Kyungseo Park contributed equally to this publication

BibTex

@article{Lee21-SMS-Piezoresistive,
  title = {Piezoresistive Textile Layer and Distributed Electrode Structure for Soft Whole-Body Tactile Skin},
  journal = {Smart Materials and Structures},
  abstract = {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.},
  volume = {30},
  number = {8},
  pages = {085036},
  month = jul,
  year = {2021},
  note = {Hyosang Lee and Kyungseo Park contributed equally to this publication},
  slug = {lee21-sms-piezoresistive},
  author = {Lee, Hyosang and Park, Kyungseo and Kim, Jung and Kuchenbecker, Katherine J.},
  month_numeric = {7}
}