Surface-enabled Manufacturing of Nanowheels for Metamaterial and Nanomotor Applications

胶体组装被认为是一种自下而上制造纳米结构的有效方法，应用范围从传感器到光子学再到生物医学设备。该奖项研究将旋转磁场应用于顺磁性纳米颗粒胶体，以形成适合组装成超材料和纳米马达的轮状簇。这个过程包括操纵颗粒间的相互作用，从而控制胶体结构的形成。该项目展示了一种制造复杂三维纳米轮子的微流控路径。纳米轮在构建光学超材料和破坏细菌生物膜方面具有潜在的应用前景。纳米车轮和纳米马达的一个潜在近期好处是它们在医学上的用途。胶体纳米轮可以通过一种物理化学机制来消融血栓，这种机制导致的溶解速度明显高于溶解血栓的药物。因此，项目成果可能会影响国民健康和福祉。纳米轮制造和翻译的研究与教育和推广项目相结合，以激励年轻学生在胶体和界面科学领域的研究。研究成果被纳入本科生和研究生课程。计划通过吸收本科生和招收有才华的未被充分代表的高中生来增强研究项目的多样性，并指导他们进入大学学习科学和工程。由于热力学和动力学方面的限制，许多想要的胶体纳米结构无法获得，因为它们的组装和从混合物中分离。该项目克服了这些限制，展示了一种微流控方法来制造不同尺寸、形状和组成的复杂三维纳米车轮。这项研究工作利用纳米车轮在具有地形图案的表面上的独特滚动行为，根据大小和形状将它们细分成纯净流。该项目的实验框架受到纳米车轮的旋转及其与适当设计的道路的相互作用的启发，为高效地组装和分离胶体簇提供了一条变革性的途径。存在于流体力学、场定向组装和摩擦学相互作用的基本纳米轮旋转机制代表了胶体组装领域的重大进步。这些研究的结果是一种新的组装方法，加快了胶体组装转化为实际应用的速度。这一奖项反映了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。

Colloidal assembly is envisioned as an effective method for the bottom-up fabrication of nanostructures for a broad range of applications from sensors to photonics to biomedical devices. This award investigates the application of rotating magnetic fields to paramagnetic nanoparticle colloids to form wheel-like clusters well suited for assembly into metamaterials and nanomotors. The process involves manipulating interparticle interactions and thus controlling colloidal structure formation. This project shows a microfluidic pathway to fabricating complex three-dimensional nanowheels. Potential applications of the nanowheels are in building optical metamaterials and disrupting bacterial biofilms. One potential near-term benefit of nanowheels and nanomotors is their use in medicine. Colloidal nanowheels can ablate blood clots using a physiochemical mechanism that results in dissolution rates significantly higher than clot dissolving drugs. Thus, the project outcomes potentially impact national health and well-being. The research on nanowheel manufacturing and translation is integrated with education and outreach programs to inspire young students in the field of colloid and interfacial science. Research results are incorporated into undergraduate and graduate courses. Plans are to enhance diversity in research programs by involving undergraduate students and recruiting talented underrepresented high school students and mentor them toward university study in science and engineering.Many desired colloidal nanostructures are inaccessible because of thermodynamic and kinetic constraints on their assembly and separation from the mixture. This project overcomes these limitations and shows a microfluidic pathway to fabricating complex three-dimensional nanowheels of different size, shape and composition. The research work takes advantage of the nanowheels' unique rolling behavior on topographically patterned surfaces to fractionate them into purified streams based on size and shape. The project's experimental framework, inspired by rotation of nanowheels and their interaction with properly designed roads, provides a transformative route to assemble and fractionate colloidal clusters efficiently. The underlying nanowheel rotation mechanism that exists at the interplay of fluid mechanics, field directed assembly, and tribology represents a significant advancement in the field of colloidal assembly. The outcome of these studies is a new assembly approach that accelerates translation of colloidal assembly into practical applications.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.