Researchers have devised a test for face masks to show which are the best at blocking droplets of fluid – and rated several current options.

In a proof-of-concept study, scientists at Duke University in Durham, North Carolina, devised a low-cost laser sensor that could spot the masks that were best at stopping droplets spreading.

The team led by Eric Westman found that medical-grade ‘N95’ masks and surgical masks performed extremely well.

Handmade cotton masks also performed well, eliminating a substantial amount of the spray from normal speech.

But improvised face coverings such as bandanas and balaclava-style face coverings were less effective, the researchers found.

Duke researchers created an ine...

Electronic filters are essential to the inner workings of our phones and other wireless devices. They eliminate or enhance specific input signals to achieve the desired output signals. They are essential, but take up space on the chips that researchers are on a constant quest to make smaller. A new study demonstrates the successful integration of the individual elements that make up electronic filters onto a single component, significantly reducing the amount of space taken up by the device.

Researchers at the University of Illinois, Urbana-Champaign have di...

Helium is the second most abundant element in the universe after hydrogen. But scientists aren’t sure just how much there actually is in the Sun’s atmosphere, where it is hard to measure. Knowing the amount of helium in the solar atmosphere is important to understanding the origin and acceleration of the solar wind—the constant stream of charged particles from the Sun.

In 2009, NASA launched a sounding rocket investigation to measure helium in the extended solar atmosphere—the first time we’ve gathered a full global map...

Materials science researchers, led by electrical engineering professor Shui-Qing “Fisher” Yu, have demonstrated the first electrically injected laser made with germanium tin. Used as a semiconducting material for circuits on electronic devices, the diode laser could improve micro-processing speed and efficiency at much lower costs.

In tests, the laser operated in pulsed conditions up to 100 kelvins, or 279 degrees below zero Fahrenheit.
“Our results are a major advance for group-IV-based lasers,” Yu said...