Researchers from the University of Cambridge have developed tiny, flexible devices that can wrap around individual nerve fibres without causing damage. These robotic nerve ‘cuffs’ combine soft robotics techniques and flexible electronics, offering new possibilities for the diagnosis and treatment of various disorders, such as epilepsy, chronic pain, or the control of prosthetic limbs.
Addressing the Limitations of Current Nerve Implants
Current tools for interfacing with peripheral nerves, which connect the brain and the spinal cord, are outdated, bulky, and carry a high risk of nerve injury. In contrast, the robotic nerve cuffs developed by the Cambridge team are sensitive enough to grasp or wrap around delicate nerve fibres without causing damage. Tests in rats showed that the devices only require tiny voltages to change shape in a controlled way, forming a self-closing loop around nerves without the need for surgical sutures or glues.
“Nerve cuffs that wrap around nerves are the least invasive implants currently available, but despite this they are still too bulky, stiff and difficult to implant, requiring significant handling and potential trauma to the nerve,” said co-author Dr Damiano Barone from Cambridge’s Department of Clinical Neurosciences.
Potential Applications and Future Possibilities
Electric nerve implants can be used to either stimulate or block signals in target nerves, potentially helping to relieve pain by blocking pain signals or restoring movement in paralysed limbs by sending electrical signals to the nerves. The researchers designed the new type of nerve cuff using conducting polymers, normally used in soft robotics. The ultra-thin cuffs are engineered in two separate layers, and applying tiny amounts of electricity causes the devices to swell or shrink.
“Using this approach, we can reach nerves that are difficult to reach through open surgery, such as the nerves that control, pain, vision or hearing, but without the need to implant anything inside the brain,” said Barone. “The ability to place these cuffs so they wrap around the nerves makes this a much easier procedure for surgeons, and it’s less risky for patients.”
The researchers are planning further testing of the devices in animal models and hope to begin testing in humans within the next few years. “The ability to make an implant that can change shape through electrical activation opens up a range of future possibilities for highly targeted treatments,” said Professor George Malliaras, who led the research. “In future, we might be able to have implants that can move through the body, or even into the brain – it makes you dream how we could use technology to benefit patients in future.”