Moshman Research helped a client design a prototype Covid-19 breathalyzer. The challenge was to focus the Covid-19 bioaerosols in an exhaled breath onto a detector chip and divert larger bioaerosols that would add noise to the measurement.

Using a focusing element, some particles would impact the detector and some would escape around and out the other side of the tube.

After tuning the dimensions, it was easy enough to focus the entire breath onto the chip. However, the challenge remained to separate out the Covid-19 bioaerosols from larger bioaerosols.

Moshman Research devised a novel solution to sort the bioaerosols by their size by observing the different spatial pattern of particles through the focus element by their size. The larger and heavier bioaerosols have more momentum after being focused to the center of the stream and are more concentrated than the lighter bioaerosols.

We leveraged this pattern of spatial spread of the bioaerosols by size with this particle sorting element. The central hole connects to exit chambers to force the larger bioaerosols out and the pie-slice gaps allow the smaller Covid-19 bioaerosols to pass around where they are re-focused on to the detector.

Our proof-of-concept was confirmed with our initial result. More than 4 times as many Covid-19 bioaerosols reached the detector than the 3 micron bioaerosols using our novel size sorting method.