Materials engineering in microwave absorbers: recent advances and prognosis

Abstract

Venerated microwave-absorbing materials (MAMs) have emerged as pivotal contenders for groundbreaking research, which are being strategically deployed to mitigate the escalating menace of electromagnetic (EM) pollution. Despite recent exhaustive cutting-edge research in this field, significant challenges still persist regarding proper comprehension and implementation of MAMs from micro- and macro-perspectives. The wide-scale adaptability of microwave absorbers (MAs) demands materials engineering-centric approach that clarifies how morphology, phase, doping, and defects govern the microwave response, while defining the pivotal role of the embedding medium in practical microwave absorption tuning. This review article deeply dissects the evolution of MAMs to date, with a panoramic view of all types of reported MAMs, offering a unique perspective of their mechanisms, design, and technology readiness. It clearly identifies the research gaps and bottleneck constraints limiting the wide-scale adaptability of MAs of each material class. The challenges of emerging MAMs with an insight into the future roadmap for their extensive deployment are traced. This article also highlights the concrete strategies to translate laboratory MAs into deployable technologies. A meticulous prognosis of the envisaged research directions for next generation MAMs, with a primary focus on the development of smart, multifunctional, multiband, and robust (SMMR) MAs for future technology applications, is presented to align with the expectations of the upcoming era for revolutionary research in the domain of MAMs.