IIT-Madras researchers develop nano-coated filter for healthcare workers treating Covid-19 patients

CHENNAI: Indian Institute of Technology Madras (IIT-M) researchers have developed a nano-coated filter media for healthcare workers treating Covid-19 patients. This filter has applications not only in healthcare but also has applications in defence and other places where air filtration of submicron particles is required.

This nano-coated filter media has been fabricated with a nylon-based polymer coating on cellulose paper and was developed through the electrospinning process. The coating properties are optimized for efficient removal of sub-micron sized dust particles in the air.

The nano-coated filter media is in the process of being field-tested in practical applications. Upon validation through field trials, it will be recommended for bulk manufacturing through industry collaborations, the institute said in a statement on Monday.

This work has been funded by Defence Research Development Organisation (DRDO) for defence applications and due to its high potential for the need of the hour, it is repositioned in health care applications.

“The nano-coating fabricated through the electrospinning process have fiber diameter less than 1 micron and can be positioned according to the need to enhance surface/depth filtration for healthcare workers or public responders. This novel filter with multiple nano-coating has capabilities to filter particles of the order of one-micron size, which is a remarkable achievement,” said Prof. K. Arul Prakash, Department of Applied Mechanics, IIT Madras.

Researchers are trying to optimize the coating parameters of nanomaterials for bulk manufacturing at an affordable cost and testing the antiviral properties for broader utilization in various applications. Also, attempts are being made to develop composite nano-coated filter media having more than one nanomaterial coating with the possibility of manufacturing multi-layered masks.

Various characteristics of the nano-coated material such as permeability (a measure of flow-through media), coating thickness, and mechanical strength have been measured. The optimized nano-coated filter media has been developed using computer tools and validated with experimental results.

An increased filtration efficiency for submicron size dust particles of the order of 0.25 microns with a marginal increase in pressure drop is a notable achievement through this technology, IIT-M said.

Prakash said nano-coated filter media have much better reverse cleanability behaviour which results in an extended service life period of air filters providing prolonged working hours for armoured vehicles.

"This will save a huge cost for defence applications where the filters are currently imported from developed countries,” he said.

The filtration can be further improved with multilayer nanomaterial coating. The nano-coated filter will not only be restricted for health care and defence applications but, in other places where air filtration of submicron particles is required. The computer simulation methodology adopted for the creation of the structure of the nanocoated filter media is also a novel development in this work.

This project was a collaborative effort with faculty from various departments of IIT Madras including Prof. Raghuram Chetty from the Department of Chemical Engineering and Prof. Saravana Kumar from the Department of Engineering Design.