Cornell University Innovates Stretchable Skin Sensors for Soft Robots and Prostheses

Researchers from Cornell University in New York City have come up with an invention that will enable soft robots and prosthetic devices to detect sensation.

In the paper submitted by Cornell University (CU) mechanical and aerospace engineering researchers, the innovation is described as fiber-optic materials developed into stretchable skin-like sensors capable of detecting sensations the way humans ordinarily do. When used as outer skin for prosthetics or soft robots, the groundbreaking invention will give such artificial devices the capability to sense and distinguish feelings such as strain, bending, and pressure every time the fiber-optic skin deforms.

The team of CU researchers were led by Robert F. Shepherd, an associate professor in CU’s Sibley School of Mechanical and Aerospace Engineering. Professor Shepherd said they are working on the commercialization of the technology as other potential medical applications of the stretchable human skin-like fiber optic sensor can be adopted in the fields of sports medicine and physical therapy.

How the CU’s Stretchable Sensors Work to Detect Skin-Like Sensations

According to the paper submitted, the stretchable fiber-optic sensor work just like regular human skin, as they it stretches and deforms. Through deformation the sensory components of the material can detect changes occurring in its optical paths. The sensors are mainly made of tubes consisting of elastomeric cores containing absorbing dyes and an RGB sensor chip.

When the tubes in the sensors deform, a light emitting diode (LED) supplies light across the elastomeric core. The RGB sensor chip inside calculates the changes transpiring in the light path across the core to act as an indicator.

Up to this point, the researchers have designed the stretchable sensors in ways that fit the finger compartments of a glove, while equipped with a battery and Bluetooth communicator. The latter allows it to communicate data about the motions in the glove and the forces that act upon the stretchable skin sensors.

Other Potential Applications of the Stretchable Skin Sensors

According to Professor Shepherd, research studies aimed at devising ways to give machines the ability to feel physically when exploring surroundings through touch is still ongoing. Once such goal is achieved successfully, their stretchable skin-like sensor invention will allow surgical robots to utilize their sense of touch in exploring other parts of the body. Such capability will enable users to feel again through their prostheses or robotic aids .

Furthermore, the stretchable skin sensor can likewise measure new kinds of data that physical therapists can use. An example presented in the paper are cases in which a physical therapist needs to measure the amount of force applied by the patient when executing a particular physical action or exercise activity. As it is such technology that can accurately measure the forces exerted is yet to be developed. The closest innovation that physical therapists utilize in evaluating the movements of patients under therapy, is the motion-tracking technology.

As explained by Professor Rob Shepherd, while sensing can be perceived by our sense of sight, measurements are not part of the usual processes if to be utilized for practical real-life purposes, The Mechanical and Aerospace Engineering professor highlighted the significance of their skin sensor invention as it will empower mechanically aided humans to perceive changes by means of touch.