When we write about stretchable sensors, the topic usually involves sensors embedded or woven in fabric used to create smart garments for humans. Researchers at Cornell University’s College of Engineering developed a stretchable fiber-optic sensor for robots. Robots that have a stretchable skin constructed with the Cornell material can detect a great deal of information about the surrounding environment based on skin deformations. The sensors detect pressure, bending, and strain, information that enables navigation in the real world as well as the identification of objects with which the robots come in contact.
As described in a paper published in Science, the current technology incorporates a pair of polyurethane elastomeric cores in a stretchable lightguide for multimodal sensing (SLIMS). One of the cores holds absorbing dyes at multiple locations. That core also connects to an LED. The other core is transparent. Each core is connected to a red-green-blue sensor chip that registers changes in optical light paths. Two cores multiply the potential to detect pressure, bending, or elongation by lighting the spaced dyes. The engineers developed a mathematical model that interprets precise locations and magnitudes by decoding decoupled data from the dual-core structure.
According to the research team, SLIMS sensors don’t require high-resolution detection, making them easier and less expensive to manufacture than distributed fiber-optic sensors. SLIMS sensors are also simpler to use with small systems such as a robot’s hand. The team also used the SLIMS sensor material in each finger of a 3D-printed glove. The glove transmits movement and deformations in real-time, giving robots a “sense of touch.”
The Cornell researchers are currently exploring opportunities to commercialize sensitive stretchable sensor-laden material in physical therapy and sports medicine. In addition, the team is looking into applications to improve virtual and augmented reality.
