Microelectrode arrays are powerful tools to record from and stimulate electrogenic cells. As a cell fires an action potential, the small space between the cell and an electrode that it is adhered to also experiences a change in potential. This can be detected as a change in potential of the electrode relative to the potential in the bulk of the culture medium. However, there is a constant trade-off in the development of high-resolution arrays, and a typical reduction in sensing efficiency of voltametric measurements with decreasing electrode size. To overcome this, we investigate novel materials such as carbon and printed conductive inks, as well as generating new nano-structured electrodes to improve the cell-device interface. Our standard MEA technology is a work-horse for the investigation of cortical and cardiac cells in vitro. These devices can be used as stand-alone measurement chips, or combined with technologies such as microfluidics, protein patterning, and optogenetics. We have developed our own multi-functional amplifier system, BioMAS, to measure from, and stimulate with these chips. The amplifier system is further compatible with gold-standard electrophysiology techiniques, such as patch-clamp and fluorescence imaging in order to verify the performance of new MEAs. This system can simultaneously operate 64 channels, providing a powerful tool for investigating neural networks.