NSF TTP-T: Direct Force Perception in Vision-Based, Robotic Tactile Sensors with Optically Programmable Liquid Crystal Elastomers

This project is funded through the NSF Translation to Practice (TTP) program, which supports efforts to translate research discoveries into practical tools that benefit communities, industry, and society. Robots are increasingly used in factories and workplaces to help address labor shortages and meet growing demands for automation, but enabling robots to feel what they are touching or interacting with remains a major unsolved challenge. This project develops a type of responsive rubber that changes its optical properties when squeezed or stretched to allow robots to directly visualize the forces they experience when interacting with their environments. By utilizing materials that undergo optical changes during deformation, this project aims to reduce the computational cost of tactile sensing and contact perception. The materials and robotics innovations this project can produce have the potential to make robots more dexterous and less expensive for deployment across manufacturing and other industries, strengthening U.S. economic competitiveness and creating new jobs. The research team will conduct fundamental materials science studies, build and test robotic sensing prototypes, and pursue commercialization of the technology, while training the next generation of scientists and engineers through research and hands-on product development experience. This project translates newly discovered, dynamic optical properties in soft liquid crystalline elastomers into sensing capabilities for robotic vision-based tactile sensors (VTSs). The research establishes processing-structure-property relationships that govern how elastomer composition and microstructure control the coupling between mechanical deformation and optical response and develops liquid crystalline alignment strategies to program force sensitivity throughout the full elastomer volume. Three objectives guide the work: (i) determine how phase separation between liquid crystalline components influence strain-induced optical transitions, (ii) investigate mesogen alignment strategies to enhance strain sensitivity, and (iii) demonstrate direct force sensing in VTS-equipped robot manipulators across complex contact scenarios including shear and slip. The anticipated outcomes include design rules for tunable optomechanical responsiveness in robotic elastomers, a scalable tactile sensing prototype, and patent filings that lay the foundation for commercial translation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.