Dexterous In-Plane Manipulation of Light-Controlled Microbots in Fluids

Light-controlled microbots are tiny robotic devices propelled and/or manipulated by light. They are typically a few micrometers to a few hundred micrometers in size and are designed to operate within aqueous environments, such as micro-fluidic channels in a biomimetic laboratory setting and ultimately, inside the human body. This study presents a unique control mechanism using light for manipulating microbots in a fluidic environment as well as the design, fabrication, and preservation of the microbots. The capacity to control microbots with a low-power laser offers an untethered and highly precise method of performing tasks in a physiological environment. To build optical traps and drive the microbots, the approach used in this study employs a spatial light modulator (SLM) and a galvanometer scanner. The efficacy of this control mechanism is demonstrated by the microbots' dexterous in-plane manipulation tasks, such as path tracking along both linear and circular patterns, rotation, and pivoting. This study, with the dexterous motion capability of light-controlled microbots, shows the feasibility of microbots being used for biomedical applications such as precise navigation in targeted drug delivery by providing a framework for optimizing the design and control of light-controlled microbots.