Acoustic Robotics Systems Lab, Institute of Robotics and Intelligent Systems, Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA.
Nat Commun. 2021 Nov 9;12(1):6455. doi: 10.1038/s41467-021-26607-y.
Cilia are short, hair-like appendages ubiquitous in various biological systems, which have evolved to manipulate and gather food in liquids at regimes where viscosity dominates inertia. Inspired by these natural systems, synthetic cilia have been developed and utilized in microfluidics and microrobotics to achieve functionalities such as propulsion, liquid pumping and mixing, and particle manipulation. Here, we demonstrate ultrasound-activated synthetic ciliary bands that mimic the natural arrangements of ciliary bands on the surface of starfish larva. Our system leverages nonlinear acoustics at microscales to drive bulk fluid motion via acoustically actuated small-amplitude oscillations of synthetic cilia. By arranging the planar ciliary bands angled towards (+) or away (-) from each other, we achieve bulk fluid motion akin to a flow source or sink. We further combine these flow characteristics with a physical principle to circumvent the scallop theorem and realize acoustic-based propulsion at microscales. Finally, inspired by the feeding mechanism of a starfish larva, we demonstrate an analogous microparticle trap by arranging + and - ciliary bands adjacent to each other.
纤毛是短而细的毛发状附属物，存在于各种生物系统中，这些纤毛已经进化到可以在以粘性为主导、惯性为辅的流场中操纵和收集液体中的食物。受这些自然系统的启发，人们已经开发并利用合成纤毛在微流控和微型机器人技术中实现了推进、液体泵送和混合以及颗粒操纵等功能。在这里，我们展示了超声激活的合成纤毛带，这些纤毛带模仿了海星幼虫表面纤毛带的自然排列。我们的系统利用微尺度下的非线性声学，通过声激活的合成纤毛的小振幅振动来驱动体流运动。通过将平面纤毛带排列成彼此朝向（+）或远离（-）的角度，我们实现了类似于流源或流阱的体流运动。我们进一步将这些流动特性与物理原理相结合，规避了扇贝定理，并在微尺度上实现了基于声的推进。最后，受海星幼虫进食机制的启发，我们通过将+和-纤毛带排列在一起，展示了类似的微粒子捕获器。
Zotero 插件
