Automated Carbon Nanotube Based Circuit Fabrication and Direct Characterization of Carbon Nanotubes Vibrations

Since their discovery, carbon nanotubes (CNTs) have fascinated many researchers due to their unprecedented properties. CNTs have found a wide range of applications in nanoelectronics, composite materials, energy conversion, and sensors. However, a major drawback in utilizing CNTs for practical applications is the difficulty in positioning or growing them at specific locations. We present a simple, rapid, non-invasive and scalable technique that enables optical imaging of CNTs. In this technique, sublimed p-Nitrobenzoic acid molecules nucleate to form optically visible nanocrystals on the sample surface. The CNTs however catalyze their formation in its vicinity by serving as a preferential nucleation site. This marking procedure enables to observe the decorated CNTs using conventional dark field optical microscopy. After the imaging the nanocrystals can be removed completely, leaving the surface intact, and the pristine CNTs electrical and mechanical properties preserved.

The high quality and the robustness of this technique allows imaging of on-surface CNTs, suspended CNTs as well as van der Waals 2D material, such as graphene and hexagonal boron nitride. Moreover, this imaging method allows also the study of the dynamic mechanical motion of long suspended CNTs. The decorated CNTs exhibit linear and non-linear behavior, and for the first time display a transition from hardening to softening regimes.