Automated circuit fabrication and direct characterization of carbon nanotubes vibrations - Optical imaging of CNTs

Since their discovery carbon nanotubes (CNTs) have fascinated many researchers due to their unprecedented electrical, optical, thermal, and mechanical properties. However, a major drawback in utilizing CNTs for practical applications is the difficulty in positioning or growing them at specific locations.
Here¹ we present a simple, rapid, non-invasive, and scalable technique that enables optical imaging of CNT. We utilize the CNTs scaffold to serve as a seed for nucleation and growth of small size, optically visible, nano-crystals. These nano-crystals can be removed completely after imaging, leaving the surface intact and thus the CNT electrical and mechanical properties are preserved. The successful and robust optical imaging allowed us to develop a dedicated image processing algorithm through which we are able to demonstrate a fully automated circuit design resulting in field effect transistors and inverters.
Moreover, we demonstrate that this imaging method allows not only to locate CNTs but also to study the dynamic mechanical motion of suspended ones. The decorated tubes exhibit linear as well as nonlinear Duffing type behavior, as well as transition from hardening to softening nonlinearity.
¹ G. Zeevi, et al., Nature Communications 7, 12153 doi: 10.1038/ncomms12153 (2016)