In the early days of the response to the COVID-19 pandemic, 3-D printing was a star performer, grabbing headlines left and right. Seemingly everyone was printing something for their local hospital.

Months later, the number of stories touting the ways that 3-D printing can be used to print personal protective equipment (PPE) and parts for ventilators has decreased. Yet the technology’s role in the fight against the virus has continued to evolve.

When COVID-19 hit, the U.S., along with the rest of the world, was caught flat-footed.  As demand for PPE exploded, supplies of face shields, ventilators, and masks became depleted.

Facing this dire set of circumstances, individuals and companies wracked their brains for how they could alleviate the situation. For those equipped with 3-D printers, the decision was simple: put them to work making parts.

Within days, hobbyists, job shops, contract manufacturers, and corporations alike were putting their additive manufacturing equipment to work to print PPE. Myriad CAD files shot around the world at the speed of light, from ventilator splitters to replacement mask concepts to face shields. The designs were often optimized for the printing process, which cut down on pre- and post-process time and effort.

Designs became tangible products almost instantly through 3-D printing. The technique is a poster child of the Industry 4.0 transition, because the machines require little to no setup time. Just load the machine with the right material, upload a well-designed CAD or slice file, input the parameters, hit print, and you’ve got parts in minutes to hours. 

Still, there were some shortcomings associated with leaning on 3-D printing to alleviate the PPE shortage. Many hospitals had to throw away donated printed parts because they didn’t meet the necessary specifications. Some 3-D printing processes, for example, weren’t capable of printing airtight parts, rendering certain mask parts unusable.

In response, the National Institute for Additive Manufacturing Innovation, National Institutes of Health, Food and Drug Administration and Department of Veterans Affairs entered into a collaboration for rapidly vetting and approving viable designs. The effort helped to standardize printing efforts. Nevertheless, many makers likely remained unaware of this clearinghouse for designs.    

Another drawback of the immediate 3-D printing response to COVID-19 was a focus on components rather than the assembly of entire products. For example, designs for printed headbands for face shields were approved, but complementary components such as transparent face shields and elastic bands were sourced through traditional channels. While the printing of such materials is possible with 3-D printers, they are typically expensive, and only readily processed by select industrial machines. This made large-scale production of those items unworkable. In time, even these limited applications were eventually boxed out, as more cost-effective solutions became available.

So was 3-D printing’s impact on the COVID-19 response a flash in the pan? Hardly. In fact, it has transitioned to becoming a behind-the-scenes input to more cost-effective production technologies.

As the PPE response highlights, 3-D printers are good at rapidly iterating on design concepts and getting tangible, functional products in hand. The initial speed and low startup cost make 3-D printing great for functional prototyping. Once the design is locked in, though, other technologies typically end up being better options. While the cost of the first 3-D-printed units is lower than that of an injection molding tool, once that tool is built, the time and variable cost per standalone unit is very low, allowing it to overtake 3-D printers if high quantities are required. Ultimately, 3-D printing’s impact on fighting COVID-19 is in support of legacy processes.

One way the technology does that is through tooling, the creation of custom instruments to aid the manufacturing process. Tooling applications vary widely, from holding a workpiece in place to ensuring proper placement of an aesthetic feature. Commonly, tools can be manufactured using consumer-friendly material extrusion desktop printers. While there are a variety of printed tooling applications, one of the most useful applications in the COVID-19 response has been the creation of 3-D printed inserts for injection mold tooling. Most notably, this is done in commercial contexts with powder bed fusion 3-D printers. Such systems are capable of printing highly complex metal inserts that can be used in injection molds. They are designed with built-in conformal cooling channels, which allow the flow of a liquid coolant — commonly water — to cool down the hot metal actively compressing the molded parts. Historically, these have been drilled in straight lines. But with printed tools, the channels can twist and turn in ways that traditional channels cannot. As a result, injection molds using these inserts cool down more rapidly, achieving faster cycle times and higher production of parts.

COVID-19 turned the spotlight on 3-D printing. Capable of rapidly iterating on new designs and manufacturing parts to address the PPE shortage, the technique proved to be a valuable and highly flexible part of early response efforts. As preferred designs were approved and locked in, 3-D printing increasingly transitioned to supporting more traditional manufacturing processes with printed tooling. Both then and now, it has played a valuable role in the manufacturing of PPE and the COVID-19 response.

Cullen Hilkene is founder and CEO of 3-Diligent.