Massachusetts Institute of Technology
An example of a 3D printed miniaturized quadrupole mass filter.
Researchers at MIT have produced a mass filter, the core component of a mass spectrometer, using 3D printing. The filter produced by the team is lighter and cheaper than the same type of filter made with traditional techniques and materials.
Mass spectrometers are devices that identify chemical substances, and are widely used in applications such as crime scene analysis, toxicology testing, and geological surveying. But the researchers from MIT say that these machines are bulky, expensive, and easy to damage, which limits where they can be effectively deployed.
The miniaturised filter, known as a quadrupole, can be 3D printed in a matter of hours for a few dollars according to the researchers. The team claims that the device is as precise as some commercial-grade mass filters that can cost upwards of 100,000 USD and take weeks to manufacture.
The device is built from durable and heat-resistant glass-ceramic resin, and no assembly is required as it is 3D printed in one step. MIT says that the lightweight, cheap, yet precise quadrupole is an important step in Luis Fernando Velásquez-García’s 20-year quest to produce a 3D printed, portable mass spectrometer.
“We are not the first ones to try to do this. But we are the first ones who succeeded at doing this. There are other miniaturised quadrupole filters, but they are not comparable with professional-grade mass filters. There are a lot of possibilities for this hardware if the size and cost could be smaller without adversely affecting the performance,” says Velásquez-García, a principial research scientist in MIT’s Microsystems Technology Laboratories (MTL) and senior author of a paper detailing the miniaturised quadrupole.
Massachusetts Institute of Technology
Velásquez-García spoke to TCT in April 2023 about a project at MIT involving researchers creating completely 3D printed sensors for satellites.
A scientist could bring a mass spectrometer to remote areas of the rainforest, using it to rapidly analyse potential pollutants without shipping samples back to a lab. A lightweight device would also be cheaper and easier to send into space, where it could monitor chemicals in Earth’s atmosphere or on those of distant planets.
Velásquez-García is joined on the paper by lead author Colin Eckhoff, an MIT graduate student in electrical engineering and computer science (EECS); Nicholas Lubinsky, a former MIT postdoc; and Luke Metzler and Randall Pedder of Ardara Technologies.
Using vat photopolymerisation 3D printing, the researchers created a quadrupole with hyperbolic rods. The team says this shape is ideal for mass filtering but is difficult to make with conventional methods, which is why many commercial filters employ rounded rods instead, which can reduce performance.
To test the 3D printed quadrupoles, the team swapped them into a commercial system and found that they could attain higher resolutions than other types of miniature filters. The researchers claim that further experiments suggest their 3D printed quadrupoles could achieve precision on par with that of large-scale commercial filters.
“Our vision is to make a mass spectrometer where all the key components can be 3D printed, contributing to a device with much less weight and cost without sacrificing performance. There is still a lot of work to do, but this is a great start,” added Velásquez-García.
The paper on this project can be found here.
