Snap-Through Buckling Bi-Stability in Suspended Carbon Nanotube Resonators

Mechanical bi-stability based on snap-through (ST) buckling is a well-known phenomenon in micro-electromechanical systems (MEMS) which serves as the underlying mechanism for many practical applications such as switches, actuators, sensors, filters, and memory elements, to name a few.
Here, we report the first realization of a suspended carbon nanotube (CNT) based bi-stable resonators exhibiting ST buckling phenomena. Both the static and dynamic responses of the system were obtained through conductance and resonance frequency measurements, respectively. In both measurements, non-linear effects such as jumps, hysteresis, softening and hardening, and super and sub-harmonic excitations were observed.
Apart from these resonators being the smallest bi-stable electromechanical system based on ST buckling to date, our devices could also serve as excellent sensors with ultrahigh sensitivities, reaching electrostatic tunability values beyond 100MHz/V, which are also attractive for realization of mechanical quantum-bits.
Finally, we developed a comprehensive theoretical model based on the Euler-Bernoulli beam equation to support our findings.