Graphene resonant sensors have shown strong competitiveness with respect to sensitivity and size. To advance the applications of graphene resonant sensors, the damage behaviors of graphene harmonic oscillators after thermal annealing and laser irradiation were investigated by morphology analysis and frequency domain vibration characteristics. The interface stress was proven to be the key factor that directly affected the yield of resonators. The resulting phenomenon could be improved by appropriately controlling the annealing temperature and size of resonators, thereby achieving membrane intactness of up to 96.4%. However, micro-cracks were found on the graphene sheets when continuous wave (CW) laser power was more than 4 mW. Moreover, the fluctuating light energy would also cause mechanical fatigue in addition to the photothermal effect, and the threshold damage power for the sinusoidally modulated laser was merely 2 mW. In this way, based on the amplitude-frequency surface morphology of the graphene resonator, the thermal time constant of the order of a few microseconds was confirmed to evaluate the damage of the graphene oscillator in situ and in real time, which could be further extended for those resonators using other 2D materials.

We demonstrate a miniature high-sensitivity Fabry-Perot (FP) acoustic assembly composed of an FP sensor with multilayer graphene diaphragm and an aided sound pressure amplification structure (SPAS). Based on the principle of force conduction amplification, the SPAS with dual 10- $\mu \text{m}$ -thickness E-shaped copper diaphragms interconnected with a 3-mm-length stepped PMMA round rod enables the acoustic sensor to exhibit up to 40.65 times higher acoustic sensitivity in the frequency range of 0.2-4 kHz compared with the reference electrical microphone, in combination with the use of anti-reflective coating for multi-beam interference suppression in FP compound cavity. Moreover, an extremely high acoustic pressure sensitivity was measured to be 1351.4 mV/Pa at 1.8 kHz with a minimum detectable sound pressure of $32.4~\mu $ Pa/Hz $^{1/2}$ , which contributes to long-distance weak sound detection application.

The art and science of magnetic electron lens design goes back to 1926 when BUSCH discovered electromagnetic fields utilized as lenses for electrons [ 1]. Conventional electromagnetic coil magnetic lenses have existed in condition to commercialize mass production throughout a century of evolution. Despite the crucial role of magnetic lens design in electron optics, the current commercial landscape is characterized by an oligopoly controlled by a few well-known companies [ 2]. However, several simulation software packages exist [ 3-7], which allow researchers to model and evaluate potential lens designs rapidly and inexpensively computationally. In this manuscript's scope, numerical simulation software capabilities have been thoroughly utilized. (here in a commercial code, COMSOL Multiphysics^®).