Living cells are arguably sophisticated unconventional computers equipped with properties difficult to archive with silicon-based computing architectures. However, limited access to (intra)cellular processes is a problem for this novel computing substrate. Although optical interfaces so far have been conventionally adopted as the common method, this often requires bulky setup, such as microscopes, and thus is hard to miniaturise the whole system. We developed an alternative interface device using the electrical impedance spectroscopy (EIS) technique to access the molecular computing processes. The plasmodium of true slime mould, Physaurm polycephalum, is interfaced to the EIS hardware, together with the microfluidic system. This enables a compact monitoring system for the cell's reactions to various external signals. At the talk, we will review our approaches for bio-hybrid devices, robot controller and biosensor, using the electrical interface and the Physarum cell.