| AVS 61st International Symposium & Exhibition | |
| MEMS and NEMS | Wednesday Sessions |
| Session MN-WeM |
| Session: | Optomechanics, Photonics, and Quantum Nanosystems |
| Presenter: | Zenghui Wang, Case Western Reserve University |
| Authors: | Z. Wang, Case Western Reserve University J. Lee, Case Western Reserve University P.X.-L. Feng, Case Western Reserve University |
| Correspondent: | Click to Email |
Higher-order and multiple modes in vibrating micro/nanomechanical resonators are of great interest and promise for both fundamental research such as exploring and understanding quantum mechanics in these man-made structures, and for technological applications such as signal processing and multi-modality sensing (e.g., simultaneously detecting mass and position of a physisorbed particle on resonator surface)[1][2] . It is therefore important to understand such multimode behavior in micro/nanomechanical resonators down to their fundamental limits, i.e. in their completely-undriven Brownian motions, at all conditions (e.g., ranging from cryogenic to elevated temperatures). This demands ultrasensitive motion transduction schemes that would allow us to attain more comprehensive information from the devices, far beyond what can be extracted from the conventional frequency-domain resonance curves.
Over the recent few decades, various motion transduction technologies (e.g., electrostatic, piezoelectric, piezoresistive, optomechanical, etc.) have been developed to read out small displacements in micro/nanomechanical resonators. While the commonly-used motion readout schemes have their respective advantages and have achieved many milestones, they lack multimode capabilities, and particularly, experimental visualizations of these multiple modes. For example, optomechanical technique has demonstrated excellent displacement sensitivity (better than fm/Hz-1/2), but is unable to experimentally determine the spatial mode shapes of 2D planar resonators, which is highly desired for determining and engineering high-order modes.
Optical interferometric techniques have been continuously advancing over the recent years [3][4]. Here, we report on the design and implementation of a scanning laser interferometry and spectromicroscopy technique, and we demonstrate direct visualization of multimode resonances in SiC micromechanical resonators with various geometries, including membranes, plates, trampolines, torsional resonators, and center-supported disks, with many resonances up in the VHF and UHF bands. Besides setting a new record of f×Q product in all SiC flexural-mode resonators (~1.0x1013), our devices effectively enable high-order resonances with clearly distinguishable mode shapes through their 2D nature and high-aspect-ratios.[1] Dohn, S., Sandberg, R., Svendsen, W. & Boisen, A. Appl. Phys. Lett. 86, 233501 (2005).
[2] Hanay, M. S. et al. Nature Nanotech. 7, 602 (2012).
[3] Hiebert ,W. K., Vick, D., Sauer, V., & Freeman, M. R. J. Micromech. Microeng. 20, 115038 (2010).
[4] Lee, J., Wang, Z., He, K., Shan, J., & Feng, P. X.-L. ACS Nano 7, 6086 (2013).