Magnetic intensity-driven frequency change of smart microcore-based hydrogen-phononic adsorber system for nanomass sensing

Abstract This study investigates the nonlocal frequency shift in an adatom-microstructure system by incorporating the effects of nonlocal elasticity, adatom distribution, and magnetic fields. The model features a sandwich microbeam composed of functionally graded porous (FGP) face sheets and a core embedded with a uniformly distributed periodic square hole (PSH) network. The material properties of all three layers vary through the thickness following a power-law distribution. The influence of the external magnetic field is modeled using Maxwell’s equations, while the small-scale effects are captured via Eringen’s nonlocal strain gradient theory. Interactions between adatoms and the substrate surface are described using Lennard–Jones (6, 12) and Morse potentials, which account for the energy changes due to adsorption. To compute the resonance frequency shift, the governing mechanical equations are formulated based on both the Euler–Bernoulli and Levinson beam models and solving the problem requires the use of the differential quadrature method (DQM) as well as Navier solution method (NSM). The results clearly demonstrate that the perforated core configuration significantly affects the frequency shift, adatom adsorption level, magnetic field intensity, and nonlocal mechanical response. These outcomes are essential for optimizing the design of mass-sensitive MEMS/NEMS resonators, including hydrogen, biomolecule, and magnetic-field sensors.