Frequency response data in the vicinity of the localised and trapped modes of a stepped fused quartz plate.

2019-08-28T11:24:59Z (GMT) by Barry Gallacher

The data sets are frequency response data obtained by exciting the localised and energy trapped modes of a stepped fused quartz plate using electromagnetic actuation via the Lorentz force. Of particular interest are the degenerate shear horizontal modes as these represent the optimal configuration for resonance based mass detection.


The data is in csv format for easy plotting in Microsoft Excel or other similar software. The frequency response data is in terms of complex amplitude response function thus enabling all type of frequency responses plots to be replotted at the reader's convenience and in the form most familiar to them e.g. magnitude (polar), Nyquist etc. The resonant frequencies can be obtained from the frequency response data and are compared with theoretical predictions obtained by a commercial finite element software package (ANSYS). The comparison is tabulated and demonstrates remarkable agreement for the family of localised and trapped modes.


The reason for obtaining the data is to confirm the existence of energy trapped degenerate modes and to distinguish them form the localised modes which stem for the finite boundary.


The data was transduced electromagnetically and a lock-in amplifier (manufactured by Zurich Instruments) was used the extract the electromagnetic signature of resonance.


The device was fabricated by INEX Micotechnology using conventional microfabrication principles. Fused quartz substrates were used as the elastic medium due to inherent high Q-factor and elastic isotropy.