AI 中文总结
本研究结合激光多普勒测振法与有限元模型，首次实验检测并重建羽纹纲、中心纲硅藻的振动本征模式，证实硅藻壳为天然共振微结构，为其在纳米力学及MEMS/NEMS中的应用开辟新方向。
AI 中文摘要
硅藻壳是硅藻微藻的分层结构、物种特异性硅质外骨骼，是自然界最复杂的自下而上自组装实例之一，具有纳米级孔隙、多功能力学和光学特性，形态多样性在尺寸上跨越近三个数量级。尽管人们对其光学和静态力学特性的兴趣日益增长，但硅藻壳的弹性动力学行为在很大程度上仍未被探索。本文结合激光多普勒测振法与基于扫描电子显微镜（SEM）和聚焦离子束扫描电子显微镜（FIB-SEM）的形态保真有限元模型，首次实验检测并空间分辨重建了硅藻壳的振动本征模式。研究选取两种形态对比的分类群作为模型系统：羽纹纲硅藻Rhaphoneis amphiceros和中心纲硅藻Stictodiscus californicus var. nitida，涵盖硅藻多样性的两大分支。在5.90-14.17 MHz范围内为R. amphiceros识别出4种本征模式，在9.96-17.62 MHz范围内为S. californicus识别出3种本征模式；模拟为每个物种生成了完整的模态图景，包括因偏离理想对称性而产生的模态分裂和近简并本征模式，且与实验测量的模态形状和共振频率定量吻合。这些结果确立硅藻壳为一类天然存在的共振微结构，并为其作为生物衍生功能元件集成到纳米力学及MEMS/NEMS应用中开辟了新途径。
英文摘要
Diatom frustules, the hierarchically structured, species-specific silica exoskeletons of diatom microalgae, are among Nature's most sophisticated examples of bottom-up self-assembly, exhibiting nanoscale porosity, multifunctional mechanical and optical properties, and a morphological diversity that spans nearly three orders of magnitude in size. Despite growing interest in their optical and static mechanical properties, the elastodynamic behaviour of frustules has remained largely unexplored. Here we report the first experimental detection and spatially resolved reconstruction of vibrational eigenmodes in diatom frustules, combining laser Doppler vibrometry with morphology-faithful finite-element models informed by scanning electron microscopy (SEM) and focused-ion-beam scanning electron microscopy (FIB-SEM). Two morphologically contrasting taxa were investigated as model systems: the pennate diatom Rhaphoneis amphiceros and the centric diatom Stictodiscus californicus var. nitida, spanning the two principal branches of diatom diversity. Four eigenmodes were identified for R. amphiceros in the 5.90-14.17 MHz range and three for S. californicus in the 9.96-17.62 MHz range; the simulations yield a complete modal landscape for each species, including modally split and nearly degenerate eigenmodes arising from deviations from ideal symmetry, and show quantitative agreement with the experimentally measured mode shapes and resonant frequencies. These results establish diatom frustules as a class of naturally occurring resonant microarchitectures, and open new avenues for their integration as bio-derived functional elements in nanomechanical and MEMS/NEMS applications.
Comments17 pages, 4 figures
