The theory of a trapped degenerate mode resonator

摘要

Resonance based biosensors are used in the detection of biological molecules for medical diagnostics. Sensing in a liquid environment is very desirable for this application, but presents a significant challenge for resonators based upon conventional technologies. In this paper, the major originality lies in the development and exposition of a fundamental theory enabling design of an original elastic resonant sensor whose modes are engineered to simultaneously possess three separate but complementary dynamical properties: namely, (1) in-plane displacement of the free interface whereby the SH waves are uncoupled from the SV and P waves; (2) intrinsic modal trapping; and finally, (3) cyclic symmetry and modal degeneracy. The modal trapping is due to the physical configuration of the resonator resulting in an imaginary wavenumber for one region of the resonator. The wave will be evanescent in this region and propagating elsewhere. The fundamental principles are elucidated, and analytical techniques are presented that facilitate the efficient design of this unique class of device. (C) 2017 Author(s).