| Characterization of Silicon Micro-Oscillators by Scanning Laser Vibrometry |
OCT 2002 |
6 pages |
| Authors:
J. F. Vignola; X. Liu; S. F. Morse; B. H. Houston; J. A. Bucaro; M. H. Marcus; D. M. Photiadis; L. Sekaric; SFA INC LANDOVER MD
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 | The dynamics of single-crystal silicon ;100 mum size rectangular paddle oscillators at room temperature have been studied using a recently developed high-resolution scanning laser vibrometer. The dynamic mechanical behavior is determined by scans of the entire device, providing both amplitude and phase spatial maps of the vibratory response. These reveal more than 16 normal modes below 500 kHz. In addition to simple translation and torsional motion, flexural modes of the ... |
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| Low Temperature Internal Friction of Diamond-Like Carbon Films |
2002 |
6 pages |
| Authors:
Xiao Liu; D. M. Photiadis; J. A. Bucaro; J. F. Vignola; B. H. Houston; Huey-Daw Wu; D. B. Chrisey; NAVAL RESEARCH LAB WASHINGTON DC
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| We have studied the internal friction of amorphous diamond-like carbon films prepared by pulsed-laser deposition from 0.4 to 300 K. The low temperature internal friction below 10K is dominated by the atomic tunnelling states for amorphous solids, which is a measure of structure disorder. We have tried to vary the content of sp3 carbon atoms versus sp2 ones by changing laser fleunce, by doping with N and Ar, and by ... |
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| Thermoelastic Loss in Microscale Oscillators |
19 DEC 2001 |
4 pages |
| Authors:
B. H. Houston; D. M. Photiadis; M. H. Marcus; J. A. Bucaro; Xiao Liu; J. F. Vignola; NAVAL RESEARCH LAB WASHINGTON DC
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| A simple model of thermoelastic dissipation is proposed for general, free standing microelectromechanical (MEMS) and nanoelectromechanical (NEMS) oscillators. The theory defines a flexural modal participation factor, the fraction of potential energy stored in flexure, and approximates the internal friction by assuming the energy loss to occur solely via classical thermoelastic dissipation of this component of the motion. The theory is compared to the measured internal friction of a high Q ... |
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| On the Modes and Loss Mechanisms of a High Q Mechanical Oscillator |
05 MAR 2001 |
4 pages |
| Authors:
Xiao Liu; S. F. Morse; J. F. Vignola; D. M. Photiadis; A. Sarkissian; M. H. Marcus; B. H. Houston; SFA INC LANDOVER MD
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| We have performed laser-Doppler vibrometry measurements of the vibration of a double-paddle oscillator. Seven modes with principally out-of-plane motion have been identified. Their resonance frequencies and mode shapes are in excellent agreement with three-dimensional finite element simulations. We have found that the second antisymmetric torsional mode has exceptionally good vibration isolation of its mode shape. This explains its extremely small low temperature internal friction below 10 K (2*10(exp -8). By ... |
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| Low Temperature Study of Loss Mechanisms of Mechanical Oscillators |
2001 |
5 pages |
| Authors:
Xiao Liu; J. F. Vignola; D. M. Photiadis; A. Sarkissian; B. H. Houston; R. D. Merithew; R. O. Pohl; NAVAL RESEARCH LAB WASHINGTON DC
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| In order to understand the loss mechanism of mechanical oscillators in micro-electromechanical systems, we have studied the temperature dependence of the quality factor Q of a high Q silicon mechanical oscillator from 0.4 K to 300 K. At temperatures above 70 K, the energy loss is principally caused by thermoelastic effect in the flexural components of the modes. Below 50 K, we find the improvements in vibration isolation guided by ... |
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