A stretchy ‘optical lace’ similar to the human body’s nervous system could give biomedical and manufacturing robots of the future a sense of touch – and the ability to sensitively adjust their actions.
Developed by PhD student Patricia Xu at Cornell University’s Organics Robotics Lab in New York State, the new synthetic material creates a ‘linked sensory network’ to enable soft robots to sense how they interact with their environment.
“We want to have a way to measure stresses and strains for highly deformable objects, and we want to do it using the hardware itself, not vision,” said lab director Rob Shepherd, the paper's senior author. “A good way to think about it is from a biological perspective. A blind person can still feel because they have sensors in their fingers that deform when their finger deforms. Robots don't have that right now.”
The lab previously created sensory foams that used optical fibres to detect such deformations. For the optical lace project, Xu used a flexible, porous lattice structure made of 3D-printed polyurethane. The researcher threaded its core with stretchable optical fibres containing more than a dozen mechanosensors, and attached an LED light to illuminate the fibres.
When Xu pressed the lattice structure at various points, the sensors were able to pinpoint changes in the photon flow. "When the structure deforms, you have contact between the input line and the output lines, and the light jumps into these output loops in the structure, so you can tell where the contact is happening," she said. "The intensity of this determines the intensity of the deformation itself."
The optical lace would act as robot ‘flesh’ rather than a skin coating, said mechanical and aerospace engineer Shepherd. The team said that robots fitted with the material would be well-suited for the health care industry, specifically beginning-of-life and end-of-life care. It could also be a promising technology for manufacturing.
The optical lace does not have as much sensitivity as human fingertips, but it is reportedly more sensitive to touch than the human back. It is also washable, and Shepherd’s lab has launched a start-up company to commercialise the technology for movement-sensing clothing for augmented reality training.
The research was published in Science Robotics.
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