Conformal ECoG array

A conformal electrocorticography array is a thin, flexible surface grid that drapes over the pia or dura and follows the folded cortical topography, rather than a stiff clinical grid that bridges across sulci and makes uneven contact. Fabricated on polyimide or parylene with hundreds to thousands of small contacts, such arrays trade the single-neuron access of penetrating probes for broad, stable, minimally penetrating coverage and mechanical intimacy with the surface.

At sufficiently high density and small contact size, flexible surface arrays can resolve fast, spatially localised signals — in some designs approaching surface-recorded unit or high-gamma activity — closing part of the gap to penetrating electrodes for tasks such as speech and motor decoding. Their appeal for chronic human use is lower tissue trauma and better conformity; their limits are depth blindness and susceptibility to surface fluid and encapsulation.