Detection of retinal signals using position sensitive microelectrode arrays

The development of high-density, multi-channel circuitry for the detection of low-level signals in particle physics has potential application in other areas of science. Here we use this technology to study biological neural networks. For example understanding the code that the retina uses to process visual images is of great interest. To this end we have fabricated a 61-channel microelectrode array on the transparent conductor indium tin oxide. We analyse the effect of contact size on electrode characteristics and demonstrate the performance of these arrays in neurophysiological experiments using retinal tissue. We present some preliminary results in the development of 519 channel arrays to allow an increased area of the retina to be studied.