Search

This study investigates the sensing characteristics of micromachined electromagnetic cantilevers vibrating at different resonance orders and under static or flowing liquid immersions. The cantilever is designed with a wide-plate structure, which contributes to the modal optimization for basic and higher-order torsions. The fluid-structure interaction is used to analyze the parameterized expressions of the density and its changing sensitivity based on the cantilever’s flexural and torsional vibrations. They have successfully clarified the comprehensive factors that influence the density measurement performance. The study shows that the analytical predictions for the density changing sensitivity agree well with the experimental results. The experiments prove that the cantilever under flowing immersion appears significantly degraded in its density measurement accuracy. Higher mode and shorter length enable the cantilever to respond better density sensing behaviors under flowing immersion. These results here can be further generalized to guide the optimal design of cantilever-based resonators in flowing liquid monitoring.

A novel magnetic field sensor is developed based on the microcantilever resonator to realize the parameter measurements of in-plane multi-axis magnetic field under different vibration modes. The working equations of the resonant sensor are established to calculate the strength and direction angle of measured magnetic field based on different resonances. The strength components of magnetic field along x-axis and y -axis are independently measured by the proposed resonant sensor under flexural and torsional resonant modes, respectively. The corresponding outputs of the sensor are linearly related to the magnetic field strength components. The finite element simulations are performed not only to prove the capability of the sensor to measure magnetic field under different modes, but also indicate the mode coupling of microcantilever resonator existed in the measurement. Thus, the coupling compensation method is proposed by amending ouput voltage of the sensor through experiments. The experimental results at atmospheric pressure show that the compensated accuracies of in-plane magnetic field are 3.06% (strength) and 1.59% (angle), and the measuring sensitivities are 98.79 µV mT−1 along x-axis and 92.46 µV mT−1 along y -axis, respectively.