Nanoelectromechanical Systems Actuators Research Articles

Photothermal operation of high frequency nanoelectromechanical systems

We describe photothermal operation of nanoelectromechanical systems (NEMS) in ambient atmosphere. Using a tightly focused modulated laser source, we have actuated the out-of-plane flexural resonances of bilayered doubly clamped beams. The optically detected displacement profiles in these beams are consistent with a model where the absorbed laser power results in a local temperature rise and a subsequent thermally induced bending moment. The described technique allows probing and actuation of NEMS with exquisite spatial and temporal resolution. From a device perspective, the technique offers immense frequency tunability and may enable future NEMS that can be remotely accessed without electronic coupling.

Characterization of nano-electro-mechanical systems (NEMS) using photoacoustic microscopy

A photoacoustic microscopy system has been developed for the noncontact characterization of materials at the micro- and nanometer scale. The system uses an electroabsoption modulated laser source for material excitation and a path-stabilized interferometer to detect the resulting displacements. Using this system, we describe the optical excitation and detection of high-frequency nanoelectromechanical systems (NEMS) at am-bient temperature and pressure. Using a tightly focused modulated laser source, we have actuated the out-of-plane flexural resonances of bi-layered doubly clamped nanomechanical beams. The optically detected displacement profiles in these beams are consistent with a model where the absorbed laser power results in a local temperature rise and a subsequent thermally induced bending moment. The excitation technique allows probing and actuation of NEMS with excellent spatial and temporal resolution. From a device perspective, the technique offers immense frequency tunability and may enable future NEMS that can be remotely accessed thus obviating the need for electronic coupling. [The authors gratefully acknowledge funding from National Science Foundation under Grants ECS-0304446 and ECS-0210752.]

Resonance frequency and quality factor tuning in electrostatic actuation of nanoelectromechanical systems

In an electro statically actuated nanoelectromechanical system (NEMS) resonator, it is shown that both the resonance frequency and the resonance quality (Q) factor can be manipulated. How much the frequency and quality factor can be tuned by excitation voltage and resistance on a doubly—clamped beam resonator is addressed. A mathematical model for investigating the tuning effects is presented. All results are shown based on the feasible dimension of the nano resonator and appropriate external driving voltage, yielding up to 20 MHz resonance frequency. Such parameter tuning could prove to be a very convenient scheme to actively control the response of NEMS for a variety of applications.