An MEA system with an agar microchamber to control the topography of network patterns of neuronal networks in single cell level has been accomplished (Figure 2C) [74]. The advantages of this combination of MEA-agar microchamber system are that it allows multiple cells firing simultaneously to be recorded for weeks without contamination, and that it allows cell positions, numbers, and their connections for cultivation to be controlled using agar microchambers with microchannels fabricated by photothermal etching where a portion of the agar layer is melted with a 1480-nm infrared laser beam. This method allows individual-cell-based neural network patterning and electrophysiological recording without cells escaping from single cell-size (8 μm) electrode positions in the single-microelectrode-size agar microchamber array.
