The Indian Institute of Technology (IIT), Kanpur has announced a breakthrough development of a novel protective layer for microwave absorbers.
The ‘Protective Layer for Microwave Metamaterial Absorbers and Method Thereof’ developed by IIT Kanpur researchers has been assigned Indian patent number 445111.
The invention is led by the team comprising Dr Kajal Chaudhary, Senior Student Research Associate at the Department of Electrical Engineering; Prof Janakarajan Ramkumar, Department of Mechanical Engineering; Prof S. Anantha Ramakrishna, Department of Physics; Prof Praveen C Ramamurthy, Department of Materials Engineering, Indian Institute of Science, Bengaluru; and Prof Kumar Vaibhav Srivastava, Department of Electrical Engineering, IIT Kanpur.
The invention is poised to transform various sectors, ranging from defense to daily living, by addressing a crucial challenge in electromagnetic wave absorption technology.
In an era of heightened waves and radar-based technologies, the ability to detect objects through reflected waves has become increasingly accurate. However, certain applications, both military and civilian, require concealing the presence of materials.
This has led to intense research into microwave metamaterial electromagnetic absorbers, particularly those utilising transparent conductive films in their design.
However, the use of such films, like Indium tin oxide coated polyethylene terephthalate (ITO-PET) sheets, has been hindered by their susceptibility to scratches and subsequent loss of conductivity over time, undermining their performance and lifespan. The new invention addresses these limitations.
Prof Abhay Karandikar, IIT Kanpur Director, said, “This novel patent is a breakthrough in the field of electromagnetic wave absorption technology. It signifies not only a remarkable technological stride but also a testament to the potential collaborative efforts across disciplines can bring. It holds the promise of making our environments safer, more secure, and less polluted by electromagnetic radiation. It can have a far-reaching impact globally.”
The patent introduces a groundbreaking solution for electromagnetic wave absorption. The current invention is a protectively coated transparent microwave metamaterial absorber that can directly be employed on optical transparent windows for electromagnetic wave absorption.
Different countries use RADAR detection technologies at microwave frequency bands for detection of any object by sensing the waves reflected back from them.
The continuous electromagnetic radiation in the environment from wifi, cell phone tower, radar, diagnostic medical equipment, and other electronic/communication systems, are dangerous for health.
The proposed protective transparent sheet is capable of absorbing more than 90% of the incident electromagnetic waves at microwave frequency,” says Prof Kumar Vaibhav Srivastava, Department of Electrical Engineering, IIT Kanpur.
The novel coatings, named PVB and APTES/PVB, bolster the mechanical reliability of metamaterial absorbers while preserving their optical and microwave capabilities.
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The result is a metamaterial absorber that remains robust even under harsh environmental conditions and rigorous handling, without compromising its microwave performance over time. Notably, coating the absorber led to a significant increase in absorption efficiency within microwave frequency range, rising from 95% to an impressive 98%.