Multielectrode arrays with elastomeric microstructured overlays for extracellular recordings from patterned neurons

Multielectrode array technology constitutes a promising approach for the characterization of the activity-dependent neuronal plasticity underlying information processing in the nervous system. For this purpose, long-term monitoring and stimulation of cultured neuronal networks with one-to-one neuron-sensor interfacing is advantageous. Existing neurochips that meet these specifications have made use of custom 3D structures requiring clean-room intensive microfabrication techniques. Low-cost fabrication procedures with potential for mass production would facilitate progress in the area. To this end, we have developed a sandwich structure comprising an elastomeric film, microstructured by replica moulding and microhole punching, for neuronal patterning, and a standard planar microelectrode array (MEA), for stimulation and recording. The elastomeric film includes microwells for cell body confinement, and microchannels capable of guiding neurites for network topology specification. The device is formed by overlaying the elastomeric structures on planar arrays. The combination of replica moulding, rapid prototyping and planar MEAs results in low-cost neurochips accessible to most neurophysiology labs. Single neuron patterning and recordings of extracellular potentials are demonstrated.