The present work envisages the development of a novel and low-cost self-mixing interferometry (SMI) technology-based single particle sensing system in a microchannel chip for real time single micro-scale particle sizing. We proposed a novel theoretical framework to describe the impulse SMI signal expression in the time domain induced by a flowing particle. Using Hilbert transform, the interferometric fringe number of the impulse SMI signal was retrieved precisely for particle size discrimination. For the ease of particle sensing, a hydrodynamic focusing microfluidic channel was employed by varying the flow rate ratio between the sample stream and the sheath liquid, and the particle stream of a controllable width was formed very easily. The experimental results presented good agreement with the theoretical values, providing a 300 nm resolution for the particle sizing measurement.

Coral-like porous Si was fabricated through the dealloying of a laser remelted as-cast AlSi12 alloy(Al-12 wt % Si). The porous Si was composed of interconnected micro-sized Si dendrites and micro/nanopores, and compared to flaky Si, which is fabricated by direct dealloying of the as-cast AlSi12 alloy. The structure of the porous Si was attributed to the dendritic solidification microstructure formed during the laser remelting process. The micropore size of the porous Si decreased from 4.2 μm to 1.6 µm with the increase in laser scanning velocity, indicating that the morphology of porous Si could be easily altered by simply controlling the laser remelting parameters. The coral-like porous Si provided enough space, making it promising for high-performance Si-based composite anode materials in lithium-ion batteries. The proposed hybrid method provides a straightforward way of tuning the porous structure in the dealloyed material.

Continuous laser irradiation of MgO presents a promising high-efficiency route for metallic magnesium production. In this work, a physics-based multiphysics fluid-dynamics model was developed and rigorously validated against 1–3 kW laser ablation experiments. The modeling results reveal a power-density-dominated reduction mechanism, where a spot radius ⩽ 0.5 mm enables sufficient plasma temperature and recoil pressure to overcome the MgO molecular dissociation barrier. Experimental results confirm a peak ablation efficiency of 53.6 mg kJ ⁻¹ and a 20% reduction rate of MgO to metallic Mg, consistent with international benchmarks. The validated model further predicts that increasing the power density to 7.64 × 10 ⁵ W cm ⁻² could achieve an energy yield of 99.0 mg kJ ⁻¹ . These findings provide mechanistic insight and predictive capability for laser-driven MgO reduction, demonstrating the strong energy-conversion potential of laser-based smelting and supporting its future industrial application.