The quality of air we inhale has significantly declined over the years. In cities like Delhi, smog during winters is a common feature. Air pollution is a real problem and it is only worsening year after year. In such a scenario, masks and air purifiers are essentials. Now imagine a situation where the properties of the two are combined? Researchers at Lovely Professional University (LPU) have done just that - they have developed Oxigeno, a biodegradable respirator combining three replaceable, purifying filters. Not just that, the respirator even produces oxygen! How? One of the filters is algae-based, which absorbs the carbon dioxide and produces oxygen.
Oxigeno has four filters - a HEPA filter (which is present in all commercial air purifiers), an activated carbon filter, a NOx and SOx filter (that filters out harmful gases) and a PTFE (Teflon) filter (to filter out small particles up to 0.44 micrometres). "The three filters come in a box that is fitted in the mask. This has to be changed every 48 hours if used continuously," says Dr Jastin Samuel, a research intensive faculty at Lovely Professional University. The respirator, for which the team has applied for a patent, was developed by BTech students Deepak Deb, Anant Kumar Rajput and Manish Kotni, under the mentorship of Dr Jastin.
Speaking about the algae-based cartridge, Dr Jastin says, "The cartridge can last up to 40 hours, if used continuously. To grow algae, there is a need for carbon dioxide and other particles which are present in the air." When asked about the smell produced by algae, Dr Jastin says, "Smell is produced only after 8 days, when the algae grows completely. There is a time limit to the cartridge and we have placed a sensor in the mask to detect algae growth and inform the user when to change the cartridge."
The respirator uses biodegradable plastic called PLA-Active, which is produced by microorganisms and can be chemically produced as well. "It can degrade within 60 to 80 days unlike other kinds of plastic. We manufacture bio-plastics in the lab at the university. We wanted the entire mask to be biodegradable. But we had to use silicon so that the user doesn't experience discomfort or irritation while wearing the mask," says Dr Jastin.
To ensure that the user can breathe easily, the researchers have placed a motor fan in the respirator. "When air is inhaled, the motor fan pushes it forward. The air passes through the HEPA filter, then goes through the activated carbon filter, then NOx and SOx filter and then the PTFE filter. Finally it will pass through the oxygen-producing algae cartridge," adds Dr Jastin.
While the respirator, which was completed in April, wasn't developed for COVID - the researchers began conceptualising it in September, last year - Dr Jastin believes that the virus won't be able to pass through the four filters. "There is a HEPA, activated carbon and PTFE filter, which shouldn't allow the Coronavirus to pass through," explains Dr Jastin. The mask, which weighs 250 grams, will cost you anywhere between Rs 2,000 to 2,200 when mass-produced. The algae cartridge costs around Rs 10 and the rest of the filters Rs 40 to 50, when mass-produced, adds Dr Jastin.
