Researchers at Cambridge University are pioneering devices which could be used to diagnose and treat a range of disorders, including epilepsy and chronic pain – even the control of prosthetic limbs – by combining flexible electronics and soft robotics.

The flexible devices can actually wrap around individual delicate nerve fibres without damaging them. Current tools for working with the peripheral nerves – the 43 pairs of motor and sensory nerves that connect the brain with the spinal cord – are outdated, bulky and carry a high risk of nerve injury.

However, the new robotic nerve “cuffs” are sensitive enough to do the job without that risk. Tests of the nerve cuffs in rats showed that the devices only require tiny voltages to change shape in a controlled way, without the need for stitches or glue.

The researchers believe they pave the way for minimally invasive monitoring and treatment for a whole range of neurological conditions. Cuffs can be used to either stimulate or block signals in target nerves. For example, they might help relieve pain by blocking pain signals, or they could be used to restore movement in paralysed limbs by sending electrical signals to the nerves. Current implants allow direct access to nerve fibres, but are risky.

“Nerve implants come with a high risk of nerve injury,” said Professor George Malliaras from Cambridge University’s Department of Engineering, who led the research. Nerves are small and highly ­delicate, so any time you put ­something large, like an electrode, in contact with them, it represents a danger to the nerves.”

The cuffs are small enough to be rolled up into a needle and injected near the target nerve. When activated electrically, the cuffs will change their shape to wrap around the nerve, allowing nerve activity to be monitored or altered. Dr Chaoqun Dong, the paper’s first author says: “What’s even more significant is these cuffs can change shape in both directions and they can be reprogrammed. This means surgeons can adjust how tightly the device fits around a nerve until they get the best results for recording and stimulating it”

Co-author Dr Damiano Barone from Cambridge’s Department of Clinical Neurosciences added: “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.”

This makes it easier for surgeons, and it’s less risky for patients. “In future, we might be able to have implants that move through the body, or into the brain – it makes you dream how we could use technology to benefit patients in future,” adds Malliaras.

It does.