Studies indicate that homemade masks help combat the spread of viruses like COVID-19 when combined with frequent hand-washing and physical distancing. Many of these studies focus on the transfer of tiny aerosol particles; however, researchers say that speaking, coughing and sneezing generates larger droplets that carry virus particles. Because of this, mechanical engineer Taher Saif said the established knowledge may not be enough to determine the effectiveness of some fabrics used in homemade masks.
Saif, a mechanical science and engineering professor at the University of Illinois, Urbana-Champaign, led a study that examined the effectiveness of common household fabrics in blocking droplets. The findings are published in the journal Extreme Mechanics Letters.
There are a plethora of masks around, homemade as well as store bought. The range of effectiveness is vast. The Journal of the American Medical Association (JAMA) suggests that face shields may be a worthwhile alternative.
Face shields come in various forms, but all provide a clear plastic barrier that covers the face. For optimal protection, the shield should extend below the chin anteriorly, to the ears laterally, and there should be no exposed gap between the forehead and the shield’s headpiece. Face shields require no special materials for fabrication and production lines can be repurposed fairly rapidly. Numerous companies, including Apple, Nike, GM, and John Deere, have all started producing face shields. These shields can be made from materials found in craft or office supply stores. Thus, availability of face shields is currently greater than that of medical masks.
In the wake of the COVID-19 pandemic, the U.S. Centers for Disease Control and Prevention recommends that people wear masks in public. Because N95 and surgical masks are scarce and should be reserved for health care workers, many people are making their own coverings. Now, researchers report in ACS Nano that a combination of cotton with natural silk or chiffon can effectively filter out aerosol particles — if the fit is good. Continue reading →