Biohybrid microalgae robots: Design, fabrication, materials, and applications

Summary

This review surveys biohybrid microrobots that use microalgae as living propulsion units coupled to engineered materials. Green microalgae are emphasized because their natural swimming and light-directed movement can provide actuation without an entirely synthetic motor. The authors also consider properties of cyanobacteria and diatoms that may be useful when constructing related robotic systems. After introducing these biological capabilities, the review examines chemical and physical methods for attaching reactive materials to algal surfaces, a key fabrication step for turning a motile organism into a functional cargo carrier or sensor. Representative applications include drug delivery, imaging, and removal of contaminants from water. By organizing the literature from organism behavior through surface modification to end use, the review explains how biological movement and artificial payloads can be co-designed. Its principal contribution is a materials-and-fabrication framework that highlights the distinct advantages of active algae-driven platforms while identifying future prospects and engineering challenges. The abstract does not provide a systematic comparison of organisms or functionalization methods, nor does it resolve biosafety, control, retrieval, manufacturing, and regulatory issues for biomedical or environmental deployment.