Implementation of a tunable hybrid system with coupled high <i>Q</i> -factor resonators based on mode localization for sensing purposes

Abstract

Abstract In this paper, we present a fully tunable system able to generate mode localization between a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>170</mml:mn> <mml:mspace width="0.25em"/> <mml:mn>000</mml:mn> <mml:mspace width="0.25em"/> </mml:math> Q -factor quartz crystal microbalance at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>1</mml:mn> <mml:mspace width="0.25em"/> <mml:mi>MHz</mml:mi> </mml:math> and a digital device (field programmable gate array) simulating in real time the presence of an identical and weakly-coupled second resonator. Indeed, this method allows to precisely select each parameter value and thus to reach the optimal configuration with the maximum sensitivity to perturbations. In addition, this design gives a perfect adaptability to the geometry of the piezoelectric resonator, that allows to work with much higher frequencies and Q -factors than conventional cantilevers or tuning-forks usually selected for the design of mode-localized sensors. The experimental sensitivities reached in this work are at least two orders of magnitude higher than the ones found in the literature, which is promising for the design of a new generation of ultrasensitive sensors based on Anderson localization.