Stretchable and High-Precision Optical Tactile Sensor for Trajectory Tracking of Parallel Mechanisms

TL;DR

This paper introduces a stretchable optical tactile sensor with superhigh spatial and force resolution, capable of precise trajectory tracking in soft robotics and human-machine interfaces.

Contribution

A novel continuous spectral-filtering based stretchable tactile sensor achieving high resolution, insensitivity to off-axis stimuli, and integration into mechanisms for real-time trajectory tracking.

Findings

High linear spatial response (0.996) during stretching and bending

Spatial resolution of 7 μm and force resolution of 5 mN

Rotational trajectory tracking with 0.02° resolution

Abstract

Stretchable sensors indicate promising prospects for soft robotics, medical devices, and human-machine interactions due to the high compliance of soft materials. Discrete sensing strategies, including sensor arrays and distributed sensors, are broadly involved in tactile sensors across versatile applications. However, it remains a challenge to achieve high spatial resolution with self-decoupled capacity and insensitivity to other off-axis stimuli for stretchable tactile sensors. Herein, we develop a stretchable tactile sensor based on the proposed continuous spectral-filtering principle, allowing superhigh resolution for applied stimuli. This proposed sensor enables a high-linear spatial response (0.996) even during stretching and bending, and high continuous spatial (7 {\mu}m) and force (5 mN) resolutions with design scalability and interaction robustness to survive piercing and cutting. We further demonstrate the sensors' performance by integrating them into a planar parallel mechanism for precise trajectory tracking (rotational resolution: 0.02{\deg}) in real time.