Tiny Robotic Nerve Cuffs Promise Breakthrough in Neurocare

Summary: Researchers have developed innovative, flexible devices that can wrap smoothly around nerve fibers, potentially transforming the diagnosis and treatment of neurological disorders. These tiny, flexible “nerve cuffs” use soft robotics and flexible electronics to interface with peripheral nerves without causing damage.

Successfully tested on rats, these cuffs adjust their shape with minimal tension, eliminating the need for surgical sutures or glues. The advance could lead to less invasive treatments for conditions such as epilepsy and chronic pain, and could improve control of prosthetic limbs.

Author:

1. Advanced materials: Nerve cuffs are made from conductive polymers used in soft robotics, allowing them to expand or contract around nerve fibers with just a few hundred millivolts of electricity.
2. Non-invasive application: The cuffs can be rolled into a needle and injected near the target nerve, where they then automatically adjust to wrap around the nerve, facilitating minimally invasive placement.
3. Future potential: The technology could enable highly targeted neurological treatments without the need for open surgery and is even being considered for accessing hard-to-reach areas inside the body.

Source: University of Cambridge

Researchers have developed tiny, flexible devices that can wrap around individual nerve fibers without damaging them.

Researchers at the University of Cambridge have combined flexible electronics and soft robotics techniques to develop devices that could be used for the diagnosis and treatment of a range of disorders including epilepsy and chronic pain, or for the control of prosthetic limbs.

Current tools for interfacing with peripheral nerves – the 43 pairs of motor and sensory nerves that connect the brain and spinal cord – are outdated, bulky and carry a high risk of nerve damage. However, the robotic nerve “cuffs” developed by the Cambridge team are sensitive enough to grasp or wrap around delicate nerve fibers without causing damage.

Tests of the nerve cuffs in rats showed that the devices require only tiny tensions to change shape in a controlled manner, forming a self-closing loop around nerves without the need for surgical sutures or glues.

Researchers say combining gentle electrical actuators with neurotechnology could be an answer to minimally invasive monitoring and treatment of a range of neurological conditions.

The results are reported in the journal Natural materials.

Electrical nerve implants can be used to stimulate or block signals in target nerves. For example, they could help relieve pain by blocking pain signals, or they could be used to restore movement to paralyzed limbs by sending electrical signals to nerves.

Nerve monitoring is also a standard surgical procedure when operating in areas of the body containing a high concentration of nerve fibers, such as anywhere near the spinal cord.

These implants allow direct access to nerve fibers, but they carry certain risks. “Nerve implants carry a high risk of nerve damage,” said Professor George Malliaras of Cambridge’s engineering department, who led the research.

“Nerves are small and very delicate, so any time you put something large, like an electrode, in contact with them, it poses a danger to the nerves.”

“Nerve cuffs that wrap around nerves are the least invasive implants currently available, but despite this, they remain too bulky, rigid and difficult to implant, requiring significant manipulation and potential trauma to the nerve,” said the co-author, Dr Damiano Barone from Cambridge Department of Clinical Neurosciences.

Researchers have designed a new type of nerve cuff made from conductive polymers, normally used in soft robotics. The ultra-thin cuffs are designed in two distinct layers. Applying small amounts of electricity (just a few hundred millivolts) causes the devices to expand or shrink.

The cuffs are small enough that they can be rolled into a needle and injected near the target nerve. When electrically activated, the cuffs change shape to wrap around the nerve, allowing nerve activity to be monitored or modified.

“To ensure the safe use of these devices inside the body, we successfully reduced the voltage required for actuation to very low values,” said Dr. Chaoqun Dong, first author of the paper.

“Even more significant is that these armbands can change shape in either direction and be reprogrammed. This means surgeons can adjust how well the device fits around a nerve until they achieve the best results for recording and stimulating the nerve.

Tests on rats showed that the cuffs could be successfully placed without surgery and formed a self-closing loop around the target nerve. The researchers plan to continue testing the devices in animal models and hope to begin human testing in the coming years.

“With this approach, we can reach nerves that are difficult to reach with open surgery, such as the nerves that control pain, vision or hearing, but without the need to implant anything at the “inside the brain,” Barone said. “The ability to place these cuffs so that they wrap around the nerves makes this procedure much easier for surgeons and less risky for patients.”

“The ability to make an implant capable of changing shape through electrical activation opens a range of future possibilities for highly targeted treatments,” Malliaras said.

“In the future, we may be able to have implants that can move around the body, or even the brain. It makes one dream of how we could use technology to benefit patients in the future.”

About this research news in neurotechnology, robotics and neurology

Author: Georges Malliaras
Source: University of Cambridge
Contact: George Malliaras – University of Cambridge
Picture: Image is credited to Neuroscience News

Original research: Free access.
“Electrochemically actuated microelectrodes for minimally invasive peripheral nerve interfaces” by George Malliaras et al. Natural materials

Abstract

Electrochemically Actuated Microelectrodes for Minimally Invasive Peripheral Nerve Interfaces

Electrode arrays that interface with peripheral nerves are used in the diagnosis and treatment of neurological disorders; however, they require complex placement surgeries that carry a high risk of nerve injury.

Here, we leverage recent advances in soft robotic actuators and flexible electronics to develop highly conformable nerve cuffs that combine electrochemically driven conductive polymer-based soft actuators with low-impedance microelectrodes.

Powered by applied voltages as low as a few hundred millivolts, these cuffs allow active gripping or wrapping around delicate nerves. We validate this technology using in vivo rat models, showing that the cuffs form and maintain a reliable, self-closing bioelectronic interface with the rats’ sciatic nerve without the use of surgical sutures or glues.

This seamless integration of gentle electrochemical actuators with neurotechnology paves the way for minimally invasive intraoperative monitoring of nerve activity and high-quality bioelectronic interfaces.