A low-cost, 61-channel µECoG array for use in rodents

Micro-Electrocorticography (μECoG) offers a minimally invasive, high resolution interface with large areas of cortex. A wide variety of μECoG designs have been developed and customized [1]-[4], including active, multiplexed arrays [5] and arrays on dissolving substrates for increased conformal contact [6]. However, designing and fabricating customized μECoG arrays requires access to microfabrication facilities, which many neuroscience labs do not have. Microfabrication is also typically labor intensive and expensive. Commercial μECoG arrays with 64 electrodes and coarser dimensions cost approximately $1000, limiting their suitability for chronic implantation in large numbers of animals. Here we present a high density (406 μm spacing), flexible (~30 μm thin), 61-contact μECoG electrode array fabricated using a low-cost, commercial manufacturing process. The array costs just $26 when ordered in quantities of 100, with the cost per electrode increasing slightly when lower quantities are ordered. Fine pitch wires minimize the size of the interconnections, enabling chronic implantation in rodents. In-house post-processing of the fabricated μECoG arrays added optional electrode coatings, such as platinum black, to reduce the electrode impedance. Our electrode design and manufacturing process dramatically improves the accessibility and reduces the cost of high-volume, high-resolution neuroscience.