Yuval E. Yaish,
Electrical and Computer Engineering
"Mode coupling, bi-stability, and spectral broadening in buckled carbon nanotube mechanical resonators"
Bi-stable mechanical resonators play a significant role in various applications, such as sensors, memory elements, quantum computing and mechanical parametric amplification. While carbon nanotube (CNT) based resonators have been widely investigated as promising NEMS devices, a bi-stable CNT resonator has never been demonstrated. In this seminar we present a new class of CNT resonators in which the nanotube is buckled upward. We show that a small upward buckling yields record electrical frequency tunability, whereas larger buckling can achieve Euler-Bernoulli (EB) bi-stability, the smallest mechanical resonator with two stable configurations to date. Furthermore, we present a three-dimensional theoretical analysis revealing significant nonlinear coupling between the in-plane and out-of-plane static and dynamic modes of motion, and a unique three-dimensional EB snap-through transition. We utilize this coupling to provide a conclusive explanation for the low-quality factor in CNT resonators at room temperature, key in understanding dissipation mechanisms at the nano scale.
Dr. Yaish is faculty at the ECE and the Zisapel Nano-Electronics Center at the Technion – Israel Institute of Technology. He earned his B.Sc. and M.Sc. in Physics from Tel-Aviv University and received his Ph.D. in Experimental Physics in Condensed Matter from the Technion. Dr. Yaish did his postdoc in Physics at Cornell University, and since then his research is focused on electrical, thermal, and mechanical properties of 1- and 2-dimensional nano scale materials such as Silicon Nanowires, Carbon Nanotubes, Graphene, and 2-dimensional van der Waals materials.