The small hairs in the image are actually nanowires. Each outgrowing thread has a diameter of 80 nanometres. The green objects climbing on the nanowires are neurons.
The electrodes of brain implants are seen by the body as foreign material. These electrodes over time are slowly surrounded by cellular material so that aquired signals become weaker and weaker. At Lund University in Sweden, researchers have developed a nanowire structure that seems to be interpreted as being native, and that promotes the growth of neurons on top of itself without the associated formation of glial cells that normally coat metal electrodes.
The structure is made out of a gallium phosphide semiconductor as the substrate with the nanowires sticking out, this pattern repeating so that the glial cells grow on the flat regions and the neurons along the nanowires. This allows the two types of cells to be nearby while staying distant enough to let the neurons have direct contact with the nanowires.
The researchers hope this technology will make brain implants stay considerably longer lasting and may also apply this technology for retinal implants in patients with damaged photoreceptors.
Study in ACS Applied Materials & Interfaces: Support of Neuronal Growth Over Glial Growth and Guidance of Optic Nerve Axons by Vertical Nanowire Arrays…
Source: Lund University…