The advancement of micro-robotics in recent years has permitted a vast field of active research and application in the biomedical sector. Latest developments in microrobotics point to some ground-breaking work using light for manufacturing as well as actuation. Optical manipulation in three-dimensional space for living biological cells in a minimally invasive manner is crucial for different biomedical applications. This article attempts to provide an overview of the accomplishments and future possibilities of light-powered microbots. An overview of the feasibility of different fabrication techniques and control modalities is compared, along with prospective applications and design considerations of light-powered microbots. A variety of challenges that still prohibit polymeric light-powered microbots from attaining their full potential are pointed out, and viable ways to overcome such challenges are proposed. This study will help future researchers to study and develop the next generation of light-actuated microbots by overcoming the current limitations and challenges in fabrication, control, and design.

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.

Untethered mobile robots at the micro-scale have the ability to improve biomedical research by performing specialized tasks inside complex physiological environments. Light-controlled wireless microbots are becoming the center of interest thanks to their accuracy in navigation and potential to carry out operations in a non-invasive manner inside living environments. The pioneering light-engineered microbots are currently in the early stage of animal trials. There is a long way ahead before they can be employed in humans for therapeutic applications such as targeted drug delivery, cancer cell diagnosis, tissue engineering, etc. The design of light-actuated microbots is one of the challenging parts along with the biocompatibility and precision control for in vivo applications. Recent progress in light-activated microbots has revealed a few innovative design concepts. In this study, we presented a framework on the different aspects with a comparative analysis of potential designs for the next generation of light-controlled microbots. Utilizing numerical simulations of fluid-structure interactions, limiting design elements of the microbots are addressed. We envision that this study will eventually facilitate the integration of robotic applications into the real world owing to the described design considerations.

The present study explores the effect of using two porous deflectors on the performance of the Savonius wind turbine compared to only one porous deflector. The numerical simulation is performed to solve the unsteady Navier-Stokes equations using the SST k-