Computer-generated implants that help nerves rewire themselves could improve the chances of restoring movement and sensation in severely injured limbs.

The "nerve guidance conduits" (NGCs) were produced by British and German engineers with a laser technique normally used to "write" complex electrical circuits.

Made from a form of biodegradable plastic, they guide regrowing nerve fibres through individual channels to aid recovery. Once the nerves are fully regrown and reconnected, the device dissolves away.

Bioengineer Professor John Haycock, from the University of Sheffield, said: "When nerves in the arms or legs are injured they have the ability to regrow, unlike in the spinal cord; however, they need assistance to do this.

"We are designing scaffold implants that can bridge an injury site and provide a range of physical and chemical cues for stimulating this regrowth."

Laboratory tests of the implants have shown that nerves will grow naturally through the channelled structure. The researchers, whose work is reported in the journal Biofabrication, are working towards clinical trials. They hope to apply the technology to a wide range of peripheral nerve injuries.

Co-author Dr Frederik Claeyssens, from the University of Sheffield's Department of Materials Science and Engineering, said: "Nerves aren't just like one long cable, they're made up of lots of small cables, similar to how an electrical wire is constructed.

"Using our new technique we can make a conduit with individual strands so the nerve fibres can form a similar structure to an undamaged nerve."

Ultimately NGCs might be developed that help in the treatment of spinal cord injury, said Dr Claeyssens.

He added: "What's exciting about this work is that not only have we designed a new method for making nerve guide scaffolds which support nerve growth, we've also developed a method of easily reproducing them through micromoulding.

"This technology could make a huge difference to patients suffering severe nerve damage."