With nine of the ten most polluted cities in the world located in India, the country is grappling with increasing pollution that is affecting the health and wealth of its people. In Delhi, the national capital, the news of increased particulate matter in the air hits the headlines very often. Although anti-pollution masks and air purifiers have gained popularity, they are often expensive and inaccessible to the common man. Now, an innovative solution from Nasofilters, a startup founded by a team from the Indian Institute of Technology Delhi, could change it all!
The engineers at Nasofilters have developed a ‘Pollution Net’ that can filter out tiny, suspended particles in the air, called particulate matter, that are smaller than 2.5 micrometres (PM2.5). The net has nanofibres that can be attached to windows or doors, much like a mosquito net. The result—clean breeze enters the house minus all the pollutants that get filtered and stay out of the window!
“We use nanofibres, which are hundreds of times smaller than normal fabric. This allows us to get a higher pore density, or an increased number of holes in the mesh, per unit area”, says Prateek Sharma, one of the founders of Nasofilters. The smaller pore size and higher density of pores per unit area mean the net can stop particles much smaller than 2.5 micrometres, while still allowing air to pass through without obstruction.
The Pollution Net has three layers. The outer layer is a hydrophobic mesh, which repels water and makes it water-resistant, providing protection against light-showers. The inner layer is a wire mesh that provides strength. “Sandwiched between these two layers is the nanofiber mesh that does the filtering”, explains Tushar Vyas, Chief Technology Officer at Nasofilters. The company claims that the net protects from particulate matter, dust, smog and even a few bacteria. The net, however, will require regular maintenance and cleaning to avoid dust and other particles from clogging up its pores.
The team had earlier developed a nasal filter that can be stuck to your nose to prevent particulate matter from entering the nose while breathing. These filters are also made using nanofibers and cost INR 10/- a piece. They can be used for up to twelve hours. Supported by the Biotechnology Industry Research Assistance Council (BIRAC), the Hong Kong Science and Technology Park (HKSTP) and the Technology Development Board, Government of India, their invention has won several awards, including the Startup National Award in 2017 awarded by the Government of India.
Although the advanced filters from Nasofilters do not affect toxic gases like carbon monoxide or poisonous metals like mercury, which are present in the air we breathe, they can help you breathe a little easy by filtering out particulate matter, which are equally dangerous.