Understanding the Dynamics of Periodic Planar Microstructures Responding to Colliding Micro-Particles

超速飞行的空气颗粒物往往会对飞机造成严重的物理冲蚀损伤，例如，冰粒或沙粒对喷气发动机涡轮叶片造成的损坏。该奖项支持理解高速粒子在表面碰撞机制的研究。刚性微粒与精密制造的微结构表面的受控碰撞将以不同的速度和角度进行。超快成像将观察到加速粒子与周期结构之间的能量交换。随着粒子能量和动量变化的力学相互作用特性将把传统光谱学的范围扩展到力学领域。将有序表面结构建模为平面超材料将有助于对这些相互作用的基本理解。这项研究的影响有可能促进工业和公共卫生部门的新工业工艺的发展，如颗粒分类和选择。在软材料中实现功能微观纹理显示出优异的粘合和摩擦性能，壁虎脚和仿生合成粘合剂的抓取能力证明了这一点。这种弹道机械超材料研究将把微结构表面的摩擦学特性的范围从准静态(亚秒区)扩展到高应变率(亚微秒区)。此外，所研究的基于合理设计的平面粘弹性微结构的机械超材料，作为粘弹性谐振器的集合，有望在机械系统中展示各种未知的非线性动力学现象，如能量吸收共振、反斯托克斯散射和几何量子化。这一研究项目将促进对机械超表面如何动态地产生界面响应的基本理解，这些响应源于粘弹性、几何相变和微结构粘结的演化。最终，所研究的能够操纵进入的微粒的散射截面的机械超材料将扩展关于可变形固体材料和结构在超高应变率机械刺激下的瞬时流变学和摩擦学行为的知识。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Speeding airborne particles often result in severe physical erosion damage in aircraft, for example damage to jet engine turbine blades caused by ice or sand particles. This award supports research to understand the mechanics of collisions of high-speed particles on surfaces. Controlled collisions of rigid microparticles against surfaces with precisely manufactured microstructures will be conducted at various speeds and angles. Energy exchanges between the speeding particles and the periodic structures will be observed with ultrafast imaging. The mechanical interaction characteristics varying with the particle’s energy and momentum will extend the scope of traditional spectroscopy to mechanics. Modeling the ordered surface structures as planar metamaterials wil further contribute to the fundamental understanding of these interactions. The impact of this research has the potential to facilitate the development of novel industrial processes, such as particle sorting and selection, in industrial and public health sectors.Implementing functional microscopic textures in soft materials has shown exceptional adhesion and friction properties, as evidenced by the gripping abilities of Gecko feet and bio-inspired synthetic adhesives. This ballistic mechanical metamaterials study will extend the scope of tribological characteristics of microstructured surfaces from the quasi-static (sub-second regime) to the high-strain rate (sub-microsecond regime). Furthermore, the researched mechanical metamaterials based on rationally designed planar viscoelastic microstructures, which serve as a collection of viscoelastic resonators, are expected to demonstrate various unexplored nonlinear dynamic phenomena, such as energy absorption resonance, anti-Stokes scattering, and geometrical quantization in the mechanical system. This research project will advance the fundamental understanding of how mechanical metasurfaces dynamically create interfacial responses originating from viscoelasticity, geometrical phase transformation, and the evolution of microstructural adhesion. Ultimately, the researched mechanical metamaterials capable of manipulating the scattering cross-section of the incoming microparticles will extend the knowledge of the transient rheological and tribological behaviors of deformable solid materials and structures when subjected to ultrahigh-strain-rate mechanical stimuli.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.