This 3D-Printed Electrospray Source Could Deliver Low-Cost At-Home Sample Analysis

Researchers from the Massachusetts Institute of Technology (MIT) have come up with a way to 3D print a key component in mass spectrometers — potentially paving the way for low-cost point-of-treatment or in-home health monitoring hardware based around the technology.

"Our big vision is to make mass spectrometry local," corresponding author Luis Fernando Velásquez-García explains, referring to a technology for analyzing samples to identify their constituent chemical components. "For someone who has a chronic disease that requires constant monitoring, they could have something the size of a shoebox that they could use to do this test at home. For that to happen, the hardware has to be inexpensive."

Traditional mass spectrometers are bulky and expensive, meaning samples need to be sent away for testing — adding both cost and time to diagnosis and monitoring. A lower-cost and more compact mass spectrometer would be invaluable, and that's that's where Velásquez-García and Alex Kachkine's work comes in: 3D-printable electrospray sources, outperforming off-the-shelf equivalents while offering the potential for major cost reductions.

"This is a do-it-yourself approach to making an ionizer, but it is not a contraption held together with duct tape or a poor man's version of the device," Velásquez-García, who works in MIT's Microsystems Technology Laboratories as a principal research scientist, claims. "At the end of the day, it works better than devices made using expensive processes and specialized instruments, and anyone can be empowered to make it."

The electrospray emitter, which fires a jet of charged particles into the spectrometer, is built using binder jet 3D printing — described by Velásquez-García as "one of the original 3D printing methods and […] highly precise" — and then subjected to electropolishing prior to being coated in zinc oxide nanowires. The resulting device is, the pair claim, able to operate at higher bias voltages than state-of-the-art equivalents and delivers up to double the signal to noise ratio in testing.

The pair's work has been published in the Journal of the American Society for Mass Spectrometry under open-access terms.