Improved Determination of Q Quality Factor and Resonance Frequency in Sensors Based on the Magnetoelastic Resonance Through the Fitting to Analytical Expressions

The resonance quality factor Q is a key parameter that describes the performance of magnetoelastic sensors. Its value can be easily quantified from the width and the peak position of the resonance curve but, when the resonance signals are small, for instance when a lot of damping is present (low quality factor), this and other simple methods to determine this parameter are highly inaccurate. In these cases, numerical fittings of the resonance curves allow to accurately obtain the value of the quality factor. We present a study of the use of different expressions to numerically fit the resonance curves of a magnetoelastic sensor that is designed to monitor the precipitation reaction of calcium oxalate. The study compares the performance of both fittings and the equivalence of the parameters obtained in each of them. Through these numerical fittings, the evolution of the different parameters that define the resonance curve of these sensors is studied, and their accuracy in determining the quality factor is compared.B.S. thanks the Basque Government for funding under the FPI grant PRE_2019_1_0200. The authors would like to thank the financial support from the Basque Government under µ4indust project (KK-2019/00101, Elkartek program) and University Basque Research Groups Funding (IT1245-19)

Accurate Determination of the Q Quality Factor in Magnetoelastic Resonant Platforms for Advanced Biological Detection

The main parameters of magnetoelastic resonators in the detection of chemical (i.e., salts, gases, etc.) or biological (i.e., bacteria, phages, etc.) agents are the sensitivity S (or external agent change magnitude per Hz change in the resonance frequency) and the quality factor Q of the resonance. We present an extensive study on the experimental determination of the Q factor in such magnetoelastic resonant platforms, using three different strategies: (a) analyzing the real and imaginary components of the susceptibility at resonance; (b) numerical fitting of the modulus of the susceptibility; (c) using an exact mathematical expression for the real part of the susceptibility. Q values obtained by the three methods are analyzed and discussed, aiming to establish the most adequate one to accurately determine the quality factor of the magnetoelastic resonance.Ana Catarina Lopes thanks MSCA-IF-2015 (Marie Sklodowska Curie Actions) of the European Union's Horizon 2020 Programme for the received funds under grant agreement no. [701852]. Ariane Sagasti wishes to thank BCMaterials Centre for financial support. Jon Gutierrez, Andoni Lasheras, and Jose Manuel Barandiaran would like to acknowledge the financial support from the Basque Government under the ACTIMAT project (Etortek 2018 program) and Research Groups IT711-13 project. Dimitris Kouzoudis is thankful for financial support under Erasmus + Mobility Agreement between the University of Patras and the University of the Basque Country (UPV/EHU). Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) is gratefully acknowledged