Fundamental Advancement and Potential Application of Stimuli Responsive Microgel

Abstract

Stimuli-responsive microgels are a versatile class of soft, cross-linked polymeric particles capable of undergoing reversible structural or volume changes when exposed to external triggers such as pH, temperature, ionic strength, enzymes, redox conditions, light, or magnetic fields. Their unique combination of swelling behavior , high water content, tunable porosity, and surface functionality makes them highly suitable for modern biomedical and technological applications. Over the past two decades, significant advancements in polymer chemistry, nanofabrication, and microfluidics have enabled the development of sophisticated microgel architectures including core–shell, hollow, hybrid, and multi-stimuli responsive systems. These engineered microgels are now widely explored for controlled drug delivery, biosensing, imaging, tissue engineering, and environmental remediation. This review provides a comprehensive overview of the historical development, chemistry, mechanisms of responsiveness, synthesis approaches, characterization methods, recent technological advancements, and diverse applications of stimuli-responsive microgels. Additionally, current challenges, limitations, and future research directions are discussed to highlight the growing potential of microgels as next-generation smart materials.