Parametric noise squeezing and parametric resonance of microcantilevers in air and liquid environments
Date of this Version6-2012
Gyan Prakash, Arvind Raman, Jeffrey Rhoads and Ronald G. Reifenberger. Rev. Sci. Instrum. 83, 065109 (2012); http://dx.doi.org/10.1063/1.4721282
In this work, parametric noise squeezing and parametric resonance are realized through the use of an electronic feedback circuit to excite a microcantilever with a signal proportional to the product of the microcantilever's displacement and a harmonic signal. The cantilever's displacement is monitored using an optical lever technique. By adjusting the gain of an amplifier in the feedback circuit, regimes of parametric noise squeezing/amplification and the principal and secondary parametric resonances of fundamental and higher order eigenmodes can be easily accessed. The exceptionally symmetric amplitude response of the microcantilever in the narrow frequency bandwidth is traced to a nonlinear parametric excitation term that arises due to the cubic nonlinearity in the output of the position-sensitive photodiode. The feedback circuit, working in both the regimes of parametric resonance and noise squeezing, allows an enhancement of the microcantilever's effective quality-factor (Q-factor) by two orders of magnitude under ambient conditions, extending the mass sensing capabilities of a conventional microcantilever into the sub-picogram regime. Likewise, experiments designed to parametrically oscillate a microcantilever in water using electronic feedback also show an increase in the microcantilever's effective Q-factor by two orders of magnitude, opening the field to high-sensitivity mass sensing in liquid environments. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4721282]
Nanoscience and Nanotechnology
Copyright 2012. American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Rev. Sci. Instrum. 83, 065109 (2012) and may be found at http://dx.doi.org/10.1063/1.4721282. The following article has been submitted to/accepted by Review of Scientific Instruments. Copyright 2012 Gyan Prakash, Arvind Raman, Jeffrey Rhoads and Ronald G. Reifenberger. This article is distributed under a Creative Commons Attribution 3.0 Unported License.