3 research outputs found
Full Electrostatic Control of Nanomechanical Buckling
Buckling at the micro and nanoscale generates distant bistable states which
can be beneficial for sensing, shape-reconfiguration and mechanical computation
applications. Although different approaches have been developed to access
buckling at small scales, such as the use heating or pre-stressing beams, very
little attention has been paid so far to dynamically and precisely control all
the critical bifurcation parameters, the compressive stress and the lateral
force on the beam. Precise and on-demand generation of compressive stress on
individually addressable microstructures is especially critical for
morphologically reconfigurable devices. Here, we develop an all-electrostatic
architecture to control the compressive force, as well as the direction and
amount of buckling, without significant heat generation on micro/nano
structures. With this architecture, we demonstrated fundamental aspects of
device function and dynamics. By applying voltages at any of the digital
electronics standards, we have controlled the direction of buckling. Lateral
deflections as large as 12% of the beam length were achieved. 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
characterized snap-through transitions between these states. The proposed
architecture opens avenues for further studies that can enable efficient
actuators and multiplexed shape-shifting devices
Performance of nano-electromechanical systems as nanoparticle position sensors
Nanoelectromechanical systems (NEMS) have been utilized as sensitive mass sensors in many applications such as single cell characterization, volatile organic biomarker detection and single molecule mass spectrometry. Using the frequency shift detection, mass of single analytes can be resolved. Mass detection sensitivity can be further improved by accurate measurement of the position, unlocking extra capabilities in nanoscale positioning and manipulation applications. Here, we studied the position sensing performance of two-mode NEMS resonators during detection of single 20 nm gold nanoparticles (GNPs). By recording the position of each particle with frequency shift sensing, the position detection accuracy was evaluated for different beam models and the results are validated by SEM imaging our results indicate that the position sensing accuracy, and therefore the mass sensing accuracy, of nanomechanical resonators depends critically on the use of appropriate beam models