Flexible Plasmonic Optical Tactile Sensor for Health Monitoring and Artificial Haptic Perception

Tactile sensors capable of quantifying mechanical stimuli through physical contact play a pivotal role in healthcare, prosthetics, and humanoid robotics. To enable conformal contact with objects of different surface morphologies, tactile sensors with high mechanical flexibility are extensively explored. Despite recent advances, most of the currently available flexible tactile sensors are based on electrical properties of functional materials, which often suffer from intrinsic limitations such as hysteresis, parasitic effects and electromagnetic interference. Herein, a flexible optical tactile sensor is presented by harnessing the unique optical properties of a soft and plasmonic optical fiber, made from composites of gold nanoparticles and elastomers. The tactile sensor is constructed by assembling the nanocomposite fiber in a sandwich structure, where sensitive and instantaneous sensing of contact force with high precision, low hysteresis, and tunable sensitivity is achieved by transducing mechanical stimuli into interpretable light signals. As demonstrations of its potential, the tactile sensor is utilized for real-time monitoring of blood pressure, respiration, as well as providing tactile mapping of diverse hand motions. To further verify the feasibility of mimicking tactile perception of human skin, the proposed sensors integrated onto a robotic hand are demonstrated to perceive hardness, roughness, and shape of objects.

Automated summary

A flexible optical tactile sensor is developed using a plasmonic optical fiber made from gold nanoparticles and elastomers. It can accurately sense contact force and convert mechanical stimuli into interpretable light signals with low hysteresis and adjustable sensitivity. The sensor is capable of real-time monitoring of blood pressure, respiration, and tactile mapping of hand motions.