The researchers’ tailored electrodes, which they call 3-D electrodes, are unique in that they are extremely soft and flexible in all three dimensions, in a way that enables stable recordings from the neurons over a long time.
The electrode is so soft that it deflects against a water surface. In order to implant such electrodes, the researchers have developed a technique for encapsulating the electrodes in a hard but dissolvable gelatine material that is also very gentle on the brain.
“This technology retains the electrodes in their original form inside the brain and can monitor what happens inside virtually undisturbed and normally functioning brain tissue”, says the author.
Until now, developed flexible electrodes have not been able to maintain their shape when implanted, which is why they have been fixated on a solid chip that limits their flexibility, among other things. Other types of electrodes that are used are much stiffer. The result in both cases is that they rub against and irritate the brain tissue, and the nerve cells around the electrodes die.
“The signals then become misleading or completely non-existent. Our new technology enables us to implant as flexible electrodes as we want, and retain the exact shape of the electrode within the brain”, says the author.
“This creates entirely new conditions for our understanding of what happens inside the brain and for the development of more effective treatments for diseases such as Parkinson's disease and chronic pain conditions than can be achieved using today’s techniques”.