This disclosure provide a nanopillar electrode device, comprising a substrate patterned with a plurality of metal pads. The device may further comprise a plurality of nanopillars electrode arrays, wherein each nanopillar electrode array is attached to the substrate above a metal pad and electrically connected to the pad. The device may further comprise and a chamber surrounding the nanopillar electrodes, which can be used for culturing cells of interest for recording action potentials. The nanopillar electrode device may be configured to apply a voltage through the nanopillar electrodes from a voltage source. Nanopillar electroporation may be used to increase the permeability of cell membranes to allow intracellular recording. Also provided are methods of device fabrication, and methods of use.