In one aspect, a microelectrode comprising an upper surface, two walls, and a polymer core is described, wherein each of the two walls forms an angle with a lower surface, and the upper surface and each of the two walls comprises a metal thin film in contact with the polymer core. The lower surface, however, lacks a continuous metal thin film.In another aspect, a microelectrode comprising a metal thin film is described in which the metal thin film has a thickness and a plane bisects the thickness. The plane forms an angle with a lower surface that lacks a contiuous metal thin film. The metal thin film is in contact with a supporting polymer having an upper surface that also lacks a continuous metal thin film.