Design, fabrication, and applications of electrostatically buckled nanomechanical systems

Abstract

Buckling is an important resource for memory and sensing applications at the micro- and nano-scale. Although di erent approaches have been developed to access buckling, such as the use of pre-stressed beams or thermal heating, none of them can dynamically and precisely control the critical bifurcation parameter |the compressive stress on the nanobeam| while keeping the heat generation and power dissipation at levels acceptable for real-life applications. Here, we develop an all-electrostatic architecture to control the compressive force, as well as the direction and amount of buckling, without heat generation. The devices, consisting of contact pads, comb-drive and beam, have been fabricated on Silicon on Insulator (SOI) chip by using micro-/nano-fabrication techniques. With this architecture, we demonstrated fundamental aspects of device function and dynamics. By applying signal voltages as low as 0.5 V, we controlled the direction of buckling to store binary information. Lateral de ections as large as 12% of the beam length were achieved, allowing nanomechanical manipulations at large deformations. We performed fatigue tests on the device which showed no discernible damage even after 10,000 buckling cycles. By modulating the compressive stress and lateral electrostatic force acting on the beam, we tuned the potential energy barrier between the post-bifurcation stable states and observed persistent transitions between the states. The proposed architecture, in this work, opens avenues for developing DC-controlled multibit nanomechanical logic gates, nano-manipulators, switches, and for studying the relationship between entropy and information.