A three dimensional biomedical probe device is provided that includes a planar substrate. A probe structure is supported on the planar substrate. The probe structure has a base and a portion essentially perpendicular to the base extending along a length to a tip and has a linear dimension at the tip of said probe structure of between 5 nanometers (nm) and 5 microns thereby defining an AC, DC, or transient current, charge, or voltage sensing probe. In one variation, this probe is the electrical contact to the biomedical medium. In another variation, this probe is also the gate electrode of a field effect transistor (FET). An array of selectively electrically addressable such devices is also provided giving the ability to sample the physiological activity at many positions within cells, fluids and intercellular regions without the need for mechanical motion and inducing cellular lysis.
