Draper, an engineering firm based in Cambridge, MA, is 3D printing with a conductive metal-based multi-material ink. The company has used the process to embed electronic devices into industrial components.
3D printing has long been used as a prototyping tool for mechanical and industrial components. With the ability to rapid prototype on a 3D printer, companies can quickly reel off several iterations of a design, put each one through its paces, and finally determine which iteration should be turned into the real thing.
With electronic components, however, things are a little different. Typically, 3D printing is best employed for plastic or metal components, limited in size, that can have complex geometries but which often do not have especially complex functions. However, with the advent of 3D printed electronics—a field pioneered by companies like Nano Dimension and Voxel8—engineers are now in a position to reel off fully functional 3D printed electronic devices at unprecedented speed.
Massachusetts-based engineering company Draper is the latest company to embrace printed electronics, with the aim of speeding up its prototyping processes and improving its end products.
“Product designers are eager to shorten the time it takes to go from concept-to-prototype-to-test in large part because their customers are asking for it,” said Draper’s Brian Smith. “If your market is looking for products in more variety, with varying capabilities and in different form factors, your product designers are on the hook to rapidly churn out prototypes. That’s not easy with the current approach to electronics manufacturing.”
The company’s solution was to equip a 3D printer with conductive metal-based multi-material inks that serve as a form of “sprayable electronics” for PCBs and other devices. Although this endeavor presented a few difficulties, the undertaking could have big benefits for the Cambridge-based firm.
“Given that electronics are fundamentally multi-material systems, the challenge lies not just in material formulation but also material-material interaction including chemical compatibility, adhesion, temperature processing, and induced stresses,” said Draper’s Peter Lewis, an expert on aerosol jet 3D printing.
With aerosol jet printing, Draper staff have been able to integrate electronics onto plastic, ceramic, and metallic structures at fine resolutions. For example, small electronic components like antennas can be printed directly onto an industrial components, reducing both fabrication and assembly time. This is helping Draper improve its existing output, but could also give it a much greater foothold in emerging technologies like Internet of Things.
One big test case for Draper involved the production of a multilayer system-on-a-chip microprocessor, which was subjected to a series of environmental and rapid aging tests. The tests involves exposing the microprocessor to thermal shock, as well as effecting temperature swings from -55°C to 125°C and carrying out moisture and insulation resistance tests.
The results of these intense tests? Draper’s 3D printed electronics remained functional through intense aging environments, which suggests that the printed device would have long lifespans when put to real-world use, while its performance in extreme temperatures also offered positive signs for the company.
Perhaps the most satisfying aspect of the 3D printed electronics testing, however, was realizing just how quickly these printed electronic devices can be made.
“Among all of our findings, we were most surprised to find that the 3D multi-material printer reduced the concept-to-prototype fabrication time for a microprocessor from many weeks and even months to just a few days,” said Robert White, an Associate Professor in the Department of Mechanical Engineering at Tufts University. “We see many uses for aerosol jet printing technology, where the entire system can be deposited on a 3D, potentially flexible substrate, and not confined to two-dimensional planes.”
Draper thinks its 3D printed electronics could be especially useful for Internet of Things (IoT) devices because such devices require “small, conformal modules” with off-the-shelf components. These devices also need to be produced quickly, and must feature simple circuit customization and revision options.
In addition to its aerosol jet printing operations, Draper claims to have developed a patent-pending hybrid 3D-microelectronics process, combining 3D printing and microelectronics.