The extendable “skin” sensor gives robots human sensations

It’s no exaggeration to say that extendable sensors could change the way soft robots work and feel. In fact, they will be able to try quite a lot.

Cornell University researchers have created a fiber optic sensor that combines low-cost LEDs and dyes, resulting in a stretchable “skin” that detects deformations such as pressure, flexion and tension. This sensor could give soft robotic systems, and anyone using augmented reality technology, the ability to experience the same rich tactile sensations that mammals depend on to navigate the natural world.

The researchers, led by Rob Shepherd, associate professor of mechanical and aerospace engineering, are working to commercialize the technology for physical therapy and sports medicine.

Their article, “Stretchable Distributed Fiber-Optic Sensors”, published in Science. The authors of the paper are PhD students Hedan Bai and Shuo Li.

Bai drew inspiration from silica-based distributed fiber optic sensors and developed an extendable light guide for multimode sensing (SLIMS). This long tube contains a pair of polyurethane elastomeric cores. A core is transparent; the other is filled with absorbent dyes in multiple locations and connects to an LED. Each core is coupled to a red-green-blue sensor chip to record geometric changes in the optical path of light.

The researchers designed a 3-D printed glove with a SLIMS sensor that runs along each finger. The glove is powered by a lithium battery and equipped with Bluetooth so that data can be transmitted to the basic software, designed by Bai, which reconstructs the movements and deformations of the glove in real time.

“Right now, the detection is mostly done by vision,” Shepherd said. “We hardly ever measure touch in real life. This skin is a way to allow ourselves and machines to measure touch interactions the way we currently use our phone cameras. It uses sight to measure touch. This is the most convenient and practical way to do it in a scalable way. “

Bai and Shepherd are working with Cornell’s Center for Technology Licensing to patent the technology, with a focus on applications in physical therapy and sports medicine. Both camps have taken advantage of motion tracking technology, but until now they have not had the ability to capture force interactions.

Researchers are also looking at ways that SLIMS sensors can enhance virtual and augmented reality experiences.

“Immersion in VR and AR is based on the acquisition of movement. Touch is barely there,” Shepherd said. “Let’s say you want to have an augmented reality simulation that teaches you how to fix your car or change a tire. If you had a glove or something that could measure pressure, as well as motion, the augmented reality display might say: “Turn and then stop, so you don’t over tighten the nuts. There is nothing out there that does it right now, but this is one way to do it. ”