20-03-2017 14:30  Electro-optics and Microelectronics Seminar

Suspended Carbon Nano-Tubes Based Nano Electro-Mechanical Systems

We address a couple of challenges for the realization of carbon nanotubes (CNTs) based devices. First is the hysteresis phenomenon and second is the difficulty in positioning the CNTs at specific locations and orientations. Undertaking the first problem, we prepare four kinds of CNTFETs and explore their hysteretic behavior. Their structure variations enable to pinpoint the physical mechanisms responsible for hysteresis. Interestingly, the fourth type of devices exhibit no hysteresis at all at ambient conditions. Tackling the second problem, we present a simple, rapid, non-invasive, and scalable technique that enables optical imaging of CNTs by the adsorption of, organic optically visible nano-crystals. After imaging, the molecules can be removed completely, leaving the surface intact while preserving the CNT electrical and mechanical properties. This technique allows also the study of dynamic mechanical motion of very long suspended CNTs in a direct fashion. Additionally, we demonstrate non-linear duffing oscillations with transition phenomenon from hardening to softening of the resonator, which adheres to a theoretical model and numerical simulations developed in our research group. We believe those newly introduced techniques alone or combined introduce essential flexibilities for the realization of novel and better devices both for science and engineering.

Location: 1061
Speaker: Michael Shlafman
Affiliation: Department of Electric Engineering Technion Back