AVS 57th International Symposium & Exhibition
    MEMS and NEMS Friday Sessions
       Session MN-FrM

Paper MN-FrM5
Theoretical and Experimental Investigation of Optically Driven Nanoelectromechanical Oscillators

Friday, October 22, 2010, 9:40 am, Room Santo Domingo

Session: Characterization for MEMS and NEMS
Presenter: R.B. Ilic, Cornell University
Authors: R.B. Ilic, Cornell University
S.L. Krylov, Tel Aviv University, Israel
H.G. Craighead, Cornell University
Correspondent: Click to Email
Actuation of biologically functional micro and nanomechanical structures using optical excitation is an emerging arena of research that couples the felds of optics, fluidics, electronics and mechanics with potential for generating novel chemical and biological sensors. In our work, we fabricated nanomechanical structures from 200nm and 250nm thick silicon nitride and single crystal silicon layers with varying lengths and widths ranging from 4μm to 12μm and 200nm to 1μm, respectively. Using a modulated laser beam, focused onto the device layer in close proximity to the clamped end of a cantilever beam, we concentrate and guide the impinging thermal energy along the device layer. Cantilever beams coupled to chains of thermally isolated links were used to experimentally investigate energy transport mechanisms in nanostructures. The nature of the excitation was studied through steady-periodic axisymmetric thermal analysis by considering a multilayered structure heated using a modulated laser source. Results were verified by finite element analysis, which was additionally implemented for the solution of steady-periodic and transient thermal, as well as steady thermoelastic problems. These theoretical investigations, coupled with our experimental results, reveal that the complex dynamics underpinning optical excitation mechanisms consist of two disparate spatial regimes. When the excitation source is focused in close proximity to the structure the response is primarily thermal. We show that as the source is placed farther from the clamped end of the structure, the thermal response progressively fades out indicating the possibility of mechanical wave propagation. Understanding the excitation mechanisms may be useful for applications including compact integration of nanophotonic elements with functionalized nanomechanical sensors for ultra-sensitive biochemical analysis.