This study investigates the development of biomimetic sound-absorbing components through laser sintering technology, drawing inspiration from wood’s natural porous structure. Using a pine wood powder/phenolic resin composite, various specimens were fabricated with different structural configurations (solid, fully porous, and varying straight-pore ratios) and cavity thicknesses. Sound absorption performance was evaluated using the impedance tube transfer function method. The effect of different composite structures, placement orientations, and cavity thicknesses on sound absorption performance was evaluated. The results demonstrate that solid laser-sintered samples exhibit inherent sound absorption properties due to microscopic pores, with absorption coefficients exceeding 0.234. The biomimetic wood-like structure, featuring multi-scale porosity at both microscopic and mesoscopic levels, shows enhanced broadband sound absorption, particularly in mid-high frequencies, with characteristic double-peak absorption curves. The study reveals that absorption performance can be optimized by adjusting structural parameters and thickness, enabling targeted frequency-specific sound absorption. This research establishes the feasibility of creating multi-frequency sound-absorbing materials using laser-sintered biomimetic wood structures, providing a foundation for future applications and development in acoustic engineering.

Polylactic acid (PLA) is a biodegradable polymer suitable for selective laser sintering, yet the atomic-level sintering mechanisms of plant-fiber-reinforced PLA remain largely unclear. Here, all-atom molecular dynamics simulations are used to investigate the sintering behavior and interfacial interactions of cotton stalk cellulose/PLA nanocomposites with cellulose contents of 0–20 wt%. The nanoparticle coalescence proceeds through three sequential stages: initial van der Waals-driven contact, thermally activated neck formation, and isothermal interfacial densification. Cellulose content exerts a non-monotonic effect on interfacial bonding. At 15 wt% cellulose, an optimal, continuous hydrogen-bond network forms between cellulose hydroxyls and PLA carbonyls, maximizing interfacial adhesion while simultaneously suppressing unfavorable dipole stacking among PLA chains. At this critical loading, cellulose acts as a rigid scaffold that directs PLA chain extension and directional migration across the sintering neck, as evidenced by atomic displacement and radius-of-gyration analyses. In contrast, excess cellulose (20 wt%) induces self-aggregation, which disrupts interfacial continuity and hinders long-range chain diffusion. These results identify 15 wt% as the optimal cellulose content for achieving enhanced interfacial bonding and chain mobility, providing atomistic criteria for the formulation design of cellulose/PLA composite powders for selective laser sintering processing.