Fig. 5

Voltage profiles recorded at the bottom surface of the array (4 × 4 mm) from neurons located at three different depths (500 μm, 1000 μm, and 1500 μm) for different via hole sizes. A: Surface mesh plot depicting the effects of the via holes (200 μm) on the voltage profile from a neuron located at a depth of 1500 μm exactly beneath the geometric center of the array. B: Voltage profiles along the diagonal axis of the array that goes through the centers of the holes and contacts. C: Relative amplitudes (recorded at the contact locations that are closest to the via hole at the array center) for different via hole sizes. Each trace is normalized by the voltage for the substrate with no holes