3D printing not everyhing: Harvard researchers find way to mass produce nasal swabs cheaply and in bulk using old-fashioned injection molding

Starting this week, some people going in for Covid-19 testing in New York City will be asked to have two swabs stuck up their noses, one a traditional plastic stick tipped with cotton or nylon, the other also a plastic stick, but one that ends in a corkscrew design rather than having something absorbent attached to it, and designed by researchers at Harvard's Wyss Institute, based at Brigham and Women's Hospital.

The researchers began working with their medical colleagues at the hospital last month after the hospital ran into the national shortage of the swabs. If it proves effective in collecting samples, it could be rushed into production, providing hundreds of thousands of inexpensive swabs with which to test people for the presence of the virus, the Harvard Gazette reports.

Other researchers have looked at using 3D printers to replace traditional swabs, which works, but which turns out is fairly expensive and limited by the fact that few fabrication plants have the 3D capacity to turn out items in the sort of quantities needed.

In contrast, the Gazette reports, the Wyss researchers have focused on injection molding, a relatively inexpensive plastics process that dates back decades and is already in common use by medical-device manufacturers: Basically, melted plastic is poured into a mold and then allowed to cool.

The Wyss scientists did use 3D printing to work out their initial design, but now have a manufacturer in California that can turn out 200,000 of the new swabs once they're approved by the FDA.