Graphene, the super thin carbon material that’s been exciting scientists in the decade+ since single-atom thick graphene crystallites were successfully extracted from the bulk material, continues to give hints of a promising future blending electronics and biology.
In a new study, conducted by researchers at the Cambridge Graphene Centre and the University of Trieste in Italy, and published in the journal ACS Nano, the suggestion is it could be used to make highly effective, flexible brain implants in future — biodevices that avoid the loss of signal problem associated with the scar tissue that can form around modern electrodes made from more rigid substances, such as silicon and tungsten.
Point is, human brains are made of soft tissue so it helps if your electrodes can flex too. Graphene is also considered to have excellent biocompatibility properties (although research into potential toxicity is not conclusive at this stage).
The implication of the Cambridge-Trieste research is that graphene-based electrodes could, in future, be safely be implanted in the brain — offering promise for the restoration of sensory functions for amputee or paralysed patients, for example, or to help individuals with motor disorders such as epilepsy or Parkinson’s disease. So the future potential being glimpsed here is pretty exciting — albeit, theoretical and a long way out (plus, it should be stressed, the successful experiments were also conducted on rat brain cultures).
The researchers note that previously other groups have shown it is possible to use treated graphene to interact with neurons in the brain, however the problem with using treated graphene was the signal to noise ratio was very low. Working with untreated graphene retains the material’s much lauded electrical conductivity — resulting in a significantly better electrode. And one that was seen to interface well with rat neurons.
“For the first time we interfaced graphene to neurons directly,” said Professor Laura Ballerini of the University of Trieste in Italy, in a statement. “We then tested the ability of neurons to generate electrical signals known to represent brain activities, and found that the neurons retained their neuronal signalling properties unaltered. This is the first functional study of neuronal synaptic activity using uncoated graphene based materials.”
The scientists couch the research as a “first step” towards using pristine graphene-based materials as an electrode for a neuro-interface. So again, graphene-based biodevices aren’t going to be coming to CES next year — perhaps in a couple of decades…
They say their next steps will be to investigate how different forms of graphene are able to affect neurons, and whether tuning the material properties might alter the biological response (in terms of synapses and neuronal excitability).
“Hopefully this will pave the way for better deep brain implants to both harness and control the brain, with higher sensitivity and fewer unwanted side effects,” added Ballerini.