Can I Pet Your Robot? Incorporating Capacitive Touch Sensing into a Soft Socially Assistive Robot Platform

TL;DR

The paper addresses adding tactile sensing to a soft social robot by embedding capacitive sensors into Blossom's crocheted exterior. It introduces a low-cost, reconfigurable tactile-skin using conductive thread, an Adafruit MPR121 capacitive sensor, and a Teensy 4.1, partitioned into nine regions for touch localization. An N=20 user study across three regions and five gestures demonstrates high detection rates (up to 96% for the top of the head) and highlights performance differences across regions, influenced by robotic mechanics and user behavior. The work offers a practical method for tactile sensing in socially assistive robotics that preserves soft, zoomorphic embodiment and enables localized touch responses, with potential extensions to soft interfaces and wearable technologies.

Abstract

This work presents a method of incorporating low-cost capacitive tactile sensors on a soft socially assistive robot platform. By embedding conductive thread into the robot's crocheted exterior, we formed a set of low-cost, flexible capacitive tactile sensors that do not disrupt the robot's soft, zoomorphic embodiment. We evaluated the sensors' performance through a user study (N=20) and found that the sensors reliably detected user touch events and localized touch inputs to one of three regions on the robot's exterior.

Figures (2)

• Figure 1: The robot's exterior features nine soft capacitive touch sensors
• Figure 2: Nine conductive thread sensors were connected to a capacitive touch sensor breakout board (Adafruit MPR121) and Teensy microcontroller