Just in time for National Cotton Candy Day!: A physicist from OIST University in Okinawa has repurposed a trusty piece of fairground culinary equipment — the humble cotton candy spinner — into an inexpensive, quick, and effective method of manufacturing N95 filters for respirators. N95s are the most effective anti-
COVID masks, filtering 95% of viruses breathed into or out of the wearer. This comes from the filter material’s non-woven nature, and its electrostatic charge; both features which make it tricky and slow to produce, leading to shortages. Enter Mahesh Bandi, with his MacGyvered method!
First, Bandi heated common plastics, like those from water bottles, as the “sugar base” analogue in the cotton candy process. Then he loaded the cotton candy machine hopper with this material, and spun the liquified plastic into a complex matrix of threads, making a mesh. The spinning process already electrostatically charged the textile a bit; Bandi later charged it fully by holding it next to an air ionizer vent. And voila: an N95-quality filter created with the ease of a county fair snack!
“Bandi tested his filters by placing several inside of surgical masks. He found the filters worked very well, but the masks were not a viable option. He then designed his own mask to allow easy insertion and removal of the filters (each mask requires three) and used a 3-D printer to produce the result. Rigorous testing (which included microscopic inspections and comparisons with N95 filters) showed the filters to be as effective at preventing inhalation of SARS-CoV-2 viruses as standard N95-type respirators.”
Bandi has published his results in Proceedings of the Royal Society A; with no plans to mass manufacture these filters himself, he hopes by offering his research, another organization with greater resources can pick up the baton. Here’s hoping this fascinating and deliciously simple technique gets wider use and helps with potential mask shortages — with the winter we’re expecting, we’re going to need all the innovation we can get.