Comparing Piezoresistive Substrates for Tactile Sensing in Dexterous Hands

TL;DR

This paper evaluates different piezoresistive materials for tactile sensing in robotic hands, demonstrating a scalable foam-based sensor that effectively detects and localizes contact during manipulation tasks.

Contribution

It introduces a novel, scalable piezoresistive foam tactile sensor for robotic hands and compares its performance with other materials in manipulation tasks.

Findings

Piezoresistive foam performs comparably to fabric sensors.

The foam-based sensor reliably detects and localizes contact.

The sensor effectively analyzes contact patterns during grasping.

Abstract

While tactile skins have been shown to be useful for detecting collisions between a robotic arm and its environment, they have not been extensively used for improving robotic grasping and in-hand manipulation. We propose a novel sensor design for use in covering existing multi-fingered robot hands. We analyze the performance of four different piezoresistive materials using both fabric and anti-static foam substrates in benchtop experiments. We find that although the piezoresistive foam was designed as packing material and not for use as a sensing substrate, it performs comparably with fabrics specifically designed for this purpose. While these results demonstrate the potential of piezoresistive foams for tactile sensing applications, they do not fully characterize the efficacy of these sensors for use in robot manipulation. As such, we use a low density foam substrate to develop a scalable tactile skin that can be attached to the palm of a robotic hand. We demonstrate several robotic manipulation tasks using this sensor to show its ability to reliably detect and localize contact, as well as analyze contact patterns during grasping and transport tasks. Our project website provides details on all materials, software, and data used in the sensor development and analysis: https://sites.google.com/gcloud.utah.edu/piezoresistive-tactile-sensing/.