How the Sensor Works
The research, published July 3 in the journal Science Advances, describes a mechanochromic tactile sensor built from a stretchable Bragg reflector sandwiched between two soft silicone layers. When an object presses into the material, its microscopic internal architecture deforms, shifting the wavelengths of light it reflects and producing spatially resolved structural colors at the exact point of contact. A standard low-cost USB camera captures those color fields directly, yielding high-resolution pressure maps without any electronic wiring, deep-learning reconstruction, or computational latency. techxplore.com science.org neurosciencenews.com
The device achieved approximately 100-micrometer resolution during testing — fine enough to image the ridges of a human fingerprint, a feat that would require thousands of individual microelectronic components under older sensor paradigms. neurosciencenews.com
From Lab Prototype to Potential Applications
“You won’t guess how much information is generated when your finger presses a light switch,” said Giacomo Sasso, the postdoctoral researcher at Queen Mary’s School of Engineering and Materials Science who invented the approach. “The key idea behind this project was to think outside the box: instead of embedding dense and overengineered sensor arrays, sensing is moved into the material itself”. techxplore.com neurosciencenews.com
Professor James Busfield, a co-author, added: “What is particularly powerful is that the information is already in the light signal. You are no longer reconstructing touch — you are observing it directly”. neurosciencenews.com
The team envisions the technology wrapping around robotic grippers in precision manufacturing, giving prosthetic limbs continuous tactile feedback, and allowing surgical systems to distinguish healthy from abnormal tissue through fine pressure signatures. techxplore.com neurosciencenews.com
A Persistent Problem Addressed
Traditional taxel-based sensors operate in real time but are limited in resolution by their physical spacing and wiring, while existing vision-based tactile sensors achieve finer detail only at the cost of heavy computation that introduces lag. The mechanochromic approach sidesteps that trade-off entirely by encoding force data directly into the light spectrum. Co-authors from the University of Florence, University of Trieste, and University of Trento collaborated on the work, merging expertise in soft robotics and polymer science. science.org neurosciencenews.com techxplore.com
