Manipulation of Optical Force-Induced Micro-Assemblies at the Air-Liquid Interface

Colloidal particles trapped by a focused laser at the air-liquid interface provide an interesting assembly dynamic. In this study, we demonstrated manipulating optical force-induced swarms via dynamic locomotion of assemblies built with holographic optical tweezers. This manipulation approach builds the foundation for autonomous control of building assemblies at the air-liquid interface, which is the first time optical micro-robots have performed this feat. Our proposed semi-autonomous control allows users to produce small dynamic secondary assemblies at the interface, which are transported to and merged with a main static assembly. This static-dynamic approach grows assemblies up to similar to 2.1 times larger than conventional methods. Manipulation and control of large-scale optical force-induced assemblies in real-time to create re-configurable swarms has the potential to lead the development of new technology and approaches for complex tasks, such as the development of new material, transportation of biological matter, studying biofilm formation created by bacteria colonies at the air-liquid interface, and more.