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Recorded September 24, 2020
Mandates for mask use in public during the recent COVID-19 pandemic, worsened by global shortage of commercial supplies, have led to widespread use of homemade masks and mask alternatives. It is assumed that wearing such masks reduces the likelihood for an infected person to spread the disease, but many of these mask designs have not been tested in practice. We have demonstrated a simple optical measurement method to evaluate the efficacy of masks to reduce the transmission of respiratory droplets during regular speech. In proof-of-principle studies, we compared a variety of commonly available mask types and observed that some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck fleece or bandanas, offer very little protection. Our measurement setup is inexpensive and can be built and operated by non-experts, allowing for rapid evaluation of mask performance during speech, sneezing, or coughing.
About the Speaker
Dr. David Grass received his PhD in physics at the University of Vienna (Austria) in the group of Professor Markus Aspelmeyer in 2018. He worked on optical methods to control micro- and nano-mechanical oscillators (optomechanics) for fundamental test of physics such as macroscopic quantum mechanics and gravity. Since 2018, he is a Postdoc in the laboratory of Professor Warren Warren at Duke University and is working on early detection of metastatic melanoma (skin cancer) with ultrafast spectroscopy and microscopy. He is a recipient of the Walter Benjamin Fellowship.