An overhanging carbon nanotube/parylene core–shell nanoprobe electrode

Abstract

A nanoprobe electrode based on electrically conductive carbon nanotube (CNT) as the core structure and biocompatible parylene-C as the insulating shell has been demonstrated. The prototype nanoprobe has been fabricated based on a local synthesis and assembly process using micromachined structures to synthesize suspended and both mechanically and electrically connected CNTs in a room temperature chamber. A 1.7-mm-long, overhanging silicon probe has been designed as the carrier for the CNT nanoprobe with typical length of a few micrometers. A conformal deposition of biocompatible parylene-C has been applied as the insulating layer and a local heating process at the distal end has been conducted to break and expose the CNT-tip section to open up the CNT core for possible electrical measurements. Experimental characterizations have shown good electrical interface between the base of the CNT and the growth-side microstructure, while the exposed CNT/parylene tip makes it attractive for applications in nano-scale electrical probing. These core–shell nanoprobe electrodes could find potential biomedical applications in intracellular electrical measurements.