High aspect ratio nanometrology using carbon nanotube probes in atomic force microscopy

Carbon nanotube (CNT) has several unique characteristics that are ideal for applying it as probe for atomic force microscopy (AFM). However, some of these characteristics make it inherently difficult to produce CNT probes. This paper developed a novel welding process that can produce nanotube probe at different lengths. The new process could control CNT probe orientation well and achieve bonding strength of greater than 306 MN/m(2). In an AFM scanning of immunoglobulin G protein and aluminum oxide, nanotube probes show better probe wear resistance, lower sample damage and a higher aspect ratio of 2.3 times than conventional silicon probes.