Researchers from Cornell University have created a stretchable skin-like material that they claim can replicate the feeling of pressure, bending, and straining. The new material is made using a fiber-optic sensor that combines low-cost LEDs and dyes.
The researchers behind the skin-like material say it could be a potential game-changer in the world of augmented reality, as it would allow users to feel sensations similar to those felt in the real world.
In coming up with the new material, the paper’s co-lead author Hedan Bai, drew inspiration from silica-based distributed fiber-optic sensors, which detect minor wavelength shifts as a way to identify multiple properties, such as changes in humidity, temperature and strain. However, silica fibers aren’t compatible with soft and stretchable electronics, meaning Bai had to come up with a new solution.
Bai’s solution was to make a stretchable lightguide for multimodal sensing (SLIMS). This entailed using a long tube that contains a pair of polyurethane elastomeric cores. One core is transparent, while the other is filled with absorbing dyes at multiple locations and connects to an LED. Each core is then coupled with a red-green-blue sensor chip to register geometric changes in the optical path of light.
“We know that soft matters can be deformed in a very complicated, combinational way, and there are a lot of deformations happening at the same time,” Bai said. “We wanted a sensor that could decouple these.”
The dual-core design increases the number of outputs by which the sensor can detect a range of deformations, including pressure, bending or elongation – by lighting up the dyes, which act as spatial encoders. The technology was then paired with a custom mathematical model able to decouple the different deformations and pinpoint their exact location and magnitude.
Take a look at the Stretchable sensor in action below:
Picture: Cornell University.