Westlake News ACADEMICS

Westlake University Lab Developed Technology to Control Assembly with Light

Intelligent Polymer Materials Laboratory, Yi FENG
08, 2020

Email: fengyi@westlake.edu.cn
Phone: +86-(0)571-85270350
Office of Public Affairs

Have you ever wondered about this when eating cheerios at breakfast: why do round Cheerios spontaneously clump together and form various patterns on the surface of the milk in your bowl? What makes them move? What causes the clumping to happen?

Known as the Cheerios Effect in fluid mechanics, it describes the phenomenon that floating cheerios attract one another. Over the past 20 years, scientists have achieved ordered assembly of micro-objects on liquid surface passively using the Cheerios Effect. However, in previous research, most of the involved assembly units are composed of nonresponsive materials, whose geometric shapes are fixed. This means that their assembly structure determined by their own geometric shape and surface wettability is impossible to dynamically tune once those nonresponsive units are placed on the liquid surface.

On this background, the intelligent polymer materials laboratory at Westlake University developed an optically controlled technology for programmable and reconfigurable assembly. Not only can it effectively control the magnitude and direction of the interaction forces between the units of assembly, it also actively reconfigures assembly structures.

The intelligent polymer materials laboratory got its inspiration to employ photo-deformable materials as building units and to develop the optically controlled assembly technology from nature: insects called Seashore Springtails (anurida maritima) which interact with each other by dynamically adjusting their body postures on the water surface and actively taking advantage of the Cheerios Effect to dynamically tune the pattern of their assembly. 

Thanks to this new assembly technology, researchers can remotely construct numerous assembly structures. According to an estimation of the intelligent polymer materials laboratory, there could be up to tens of thousands of assembly structures with merely nine units. Using the new technology, researchers will be able to manipulate assembly structures as they wish.

The development of this new assembly technology may also inspire scientists and engineers to employ modular components that allow spontaneous and programmable assembling of fully equipped multifunctional robots or other devices.

Moreover, the technology enables collaborative assembly across two adjacent liquid interfaces, and thus realizes the construction of programmed 3D-ordered structures. These 3D-synergistic assemblies provide a versatile approach to fabricate novel hierarchical devices and architectures, which have great potential for technologically significant applications. For example, in bioengineering, such 3D-synergistic assemblies could be applied to dynamic construction of multi-level gradient scaffold structures to cultivate cells and tissues.

These findings were published on Nature Communications on Nov. 13th, 2020. The first authors of the paper are Zhiming Hu, PhD student at Westlake University, and Wei Fang, PhD student at Tsinghua University. Jiu'an Lv, the principal investigator of the intelligent polymer materials laboratory at Westlake University, and Professor Xiqiao Feng from the Department of Engineering Mechanics of Tsinghua University are corresponding authors of the paper. 

Link to the article:https://www.nature.com/articles/s41467-020-19522-1