ERI: Engineering self-assembled responsive materials by employing light-driven shapeshifting of colloidal particles

微观响应材料可以改变其形状以响应来自环境的刺激，具有许多变革性的应用。由于昂贵的工具（如高分辨率3D打印机）的成本以及目标3D形状多样性的限制，目前制造响应微结构的技术面临着重大挑战。该奖项将研究基于自组装过程的廉价替代制造方法的潜力。在自组装过程中，材料的小积木在没有人为干预的情况下将自己组织成功能结构。通过使用响应性积木，可以根据需要重新配置自组装结构的形状。由于自组装提供了在构建块水平上获得材料响应的途径以及根据需要组装和拆卸的灵活性，因此它是解决小规模响应材料设计的工程挑战的有希望的候选者。该奖项将提供机会，培养本科生和硕士生在CSUF（西班牙裔服务机构）成为高技能的研究人员和工程研究的未来领导者。它还将使更广泛的社区参与尖端软材料研究。 胶体粒子，改变其形状响应于光将被用来研究响应自组装，重点是塑造全球结构使用局部调整的颗粒形状。一个新的实验系统将被开发，允许静态和动态图案化的光照明的胶体组件。该奖项的具体目标是（1）测试有序胶体晶体可以通过位错的发射和迁移形成的假设，以及（2）研究无序胶体团簇的变形。此外，将开发一个数值模型，以了解胶体相互作用范围和强度对变形动力学的影响。到目前为止，响应自组装的实验已经研究了全球形状重构的背景下。该奖项将允许测试的理论预测表明，控制局部颗粒形状将导致有趣的全球行为与缺陷工程，胶体机器人技术和活性物质的研究中的应用。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Microscopic responsive materials that can change their shapes in response to stimuli from the environment have many transformative applications. The current technology of manufacturing responsive microstructures faces significant challenges due to the cost of expensive tools, such as high-resolution 3D printers, and limitation in the diversity of target 3D shapes. This award will investigate the potential of an inexpensive alternative manufacturing method based on self-assembly process. In a self-assembly process, the small building blocks of a material organize themselves into a functional structure without human intervention. By using responsive building blocks, the shape of a self-assembled structure can be reconfigured on demand. Because self-assembly provides access to the material response at a building-block level and the flexibility to assemble and disassemble on demand, it is a promising candidate for solving the engineering challenges of responsive material design at small scales. This award will provide opportunities to train undergraduate and Masters’ students at CSUF (a Hispanic-serving Institution) into highly skilled researchers and future leaders of engineering research. It will also engage the broader community in cutting-edge soft materials research. Colloidal particles that change their shape in response to light will be employed to investigate responsive self-assembly, with a focus on shaping the global structure using local tuning of particle shapes. A new experimental system will be developed that allows for static and dynamic patterned light illumination on colloidal assemblies. The specific goals of this award are (1) to test the hypothesis that ordered colloidal crystals can be shaped through emission and migration of dislocations, and (2) to investigate shapeshifting of disordered colloidal clusters. In addition, a numerical model will be developed to understand the impact of colloidal interaction range and strength on the shapeshifting dynamics. To date, experiments on responsive self-assembly have been studied only in the context of global shape reconfiguration. This award will allow testing of theoretical predictions suggesting that control over local particle shapes will lead to intriguing global behavior with applications in defect engineering, colloidal robotics, and the study of active matter.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.