# Color-Coded Fiber-Optic Tactile Sensor for an Elastomeric Robot Skin

## TL;DR

This paper introduces a color-coded fiber-optic tactile sensor for elastomeric robot skin, enabling contact localization and force sensing with robustness and potential for tactile exploration.

## Contribution

The work presents a novel fiber-optic tactile sensor using color coding and machine learning for contact localization and force measurement in robotic skin.

## Key findings

- Force sensing range up to 18 N
- Force resolution around 3.6 N
- Spatial resolution of 8 mm

## Abstract

The sense of touch is essential for reliable mapping between the environment and a robot which interacts physically with objects. Presumably, an artificial tactile skin would facilitate safe interaction of the robots with the environment. In this work, we present our color-coded tactile sensor, incorporating plastic optical fibers (POF), transparent silicone rubber and an off-the-shelf color camera. Processing electronics are placed away from the sensing surface to make the sensor robust to harsh environments. Contact localization is possible thanks to the lower number of light sources compared to the number of camera POFs. Classical machine learning techniques and a hierarchical classification scheme were used for contact localization. Specifically, we generated the mapping from stimulation to sensation of a robotic perception system using our sensor. We achieved a force sensing range up to 18 N with the force resolution of around 3.6~N and the spatial resolution of 8~mm. The color-coded tactile sensor is suitable for tactile exploration and might enable further innovations in robust tactile sensing.