A new neural probe using SOI wafers with topological interlocking mechanisms

A new method of fabricating multielectrode arrays on undoped single-crystal silicon for use in electrical stimulation and recording of nerve signals has been developed. The microscale topological design of grooves and dimples in the surface of the probes minimize differential movement in response to external stress by mechanical anchoring. The key function of topological controls is to promote the integration of microelectrodes with neural tissue in order to improve the effective electrical stimulation and signal-to-noise ratio. An adhesion peel test between PDMS and silicon is used as a simple model of this interface. Results show a 2-5 times increase in adhesion between the polymer and silicon surface when a patterned area was compared to a plain unpatterned area. This significant increase in adhesion strength without chemical modification indicates a robust mechanism by which neural tissue can bind to neural probes. The probes fabricated here are tested in an animal model.