On-chip neural cell cultivation using agarose-microchamber array constructed by a photothermal etching method

We have developed a novel method for on-chip cultivation of neural cells in a flexible agarose-microchamber array on a glass slide. The agarose microchamber is a micrometer-order cavity constructed on the surface of an agarose layer by molding a 50-μm-high square/circular micro-cast of thick SU-8 photoresist. In addition, the shape of the agarose microchamber was rearranged by using the photothermal etching method, in which we used an infrared (1064-nm) focused laser beam as the heat source to melt and remove a portion of agarose gel at the heating spot. With the photothermal etching method, we can also manufacture narrow tunnel-shaped channels between microchambers. When nerve cells were cultured on the agar-microchamber array chip, the nerve cells in two adjacent microchambers connected through the photothermal-etched channel after 48 hours of cultivation. Those results suggest the potential of an agarose-microchamber array integrated with the photothermal etching method for the next stage of single cell cultivation and measurement of nerve cells, such as real-time control of cell interactions during cultivation.