Rapid Diagnostics Device Developed Using Figure 4 Standalone

Product: DLP Print
Industry: Electronics and Semiconductors

The sudden and alarming global rise of COVID-19 has highlighted the importance of accessible and rapid disease detection. The ability to test for disease not only enables better containment to prevent further spread, but enables epidemiologists to gather more information to better understand an otherwise invisible and mysterious threat. From revealing means of transmission to rates of infection, the criticality of testing for infectious diseases has now been felt worldwide.

A team of researchers at Imperial College London, led by Dr. Pantelis Georgiou, is tackling this problem head-on with a project called Lacewing for pathogen detection. Offering results within 20 minutes from a smartphone app synced to a cloud server, Lacewing makes disease testing portable, including SARD-CoV-2-RNA, and automates the tracking of disease progression through geotagging. It is a sophisticated “lab-on-a-chip” platform that promises to fill the access- and information-gaps in the world of diagnostics by combining molecular biology and state-of-the-art technology. Whereas other diagnostics technology requires large and expensive optical equipment, the electrical sensing method and small size of Lacewing is a true evolution in approach.

Key among the technologies behind Lacewing is 3D Systems Figure 4® Standalone 3D printer and biocompatible-capable, production-grade materials. Used for both prototyping and production of microfluidics and functional components, Imperial College PhD student and research assistant Matthew Cavuto says key Lacewing components were designed based on the capabilities he knew he had with Figure 4. “Microfluidics are a tricky thing, and fabrication has traditionally been done through slow, expensive, and labor intensive cleanroom processes,” says Cavuto. “With the Figure 4, we’re now able to rapidly print parts with complex internal 3D fluidic channels for transporting sample fluid to different sensing areas on the chip, greatly improving our microfluidic production capabilities.”

As critical as the design element is to this project, it is just one piece of a highly sophisticated solution. Beyond the part complexity and detail fidelity enabled by 3D Systems’ Figure 4, this 3D printing solution has helped the research team through print speed, print quality, and biocompatible material options.

Microfluidics cartridge for Lacewing diagnostics device 3D printed using Figure 4

Quick iterations to answer the need for COVID-19 testing

The Lacewing platform has been in development for a little over two years now, and is a molecular diagnostic test that works by identifying the DNA or RNA of a pathogen within a patient sample. This type of test makes it possible to determine not only if someone is infected with a certain disease (dengue, malaria, tuberculosis, COVID-19, etc.), but to what degree, which provides more insight into the severity of the symptoms.

Prior to the outbreak of COVID-19, the impetus for this test was to enable portable testing in remote areas of the world. Although portability is often taken for granted in a smartphone age, molecular diagnostics have traditionally required a large and expensive pieces of lab equipment. Lacewing has replaced the previous optical technique with an electrical one using microchips, and has been quickly prototyped, iterated, and produced using the Figure 4 Standalone and biocompatible materials. Each Lacewing microfluidic cartridge is roughly 30 mm x 6 mm x 5 mm, printed in 10-micron layers.

As the research team began adapting the test to answer the global testing needs of COVID-19, it started printing new designs almost daily. For this, Cavuto said the speed of the machine was a major benefit. “At one point, I was able to print and test three versions of a particular component in a single day with the Figure 4,” he says. This ability to rapidly iterate designs has removed the friction of trying something new, and the resulting experimentation and increased information gathering has led to improvements in the overall system. “We’ve easily gone through 30 versions in the last 2 months,” says Cavuto.

The team designs all its parts in SOLIDWORKS, and uses 3D Sprint® software to set up each build. 3D Sprint is an all-in-one software by 3D Systems for preparing, optimizing, and managing the 3D printing process, and it has been useful to the research team in finding and resolving unexpected issues. “Occasionally we’ll get an STL error that 3D Sprint can solve for us in the prepare tab,” says Cavuto. 

Having worked with many different 3D printers in the past, Cavuto says Figure 4 is different because there are less barriers to printing in terms of time, cost, and quality. With other printers, he would question whether a print was worthwhile in terms of both time and material cost, whereas Figure 4 has removed that friction. “I print a part, and see if it works. If it doesn’t, I redesign and print again just a few hours later,” says Cavuto. “I’m able to iterate super quickly just because of how fast the printer is.”

Truly biocompatible materials do not inhibit chemical reaction

 Microfluidics cartridge 3D printed in Figure 4 MED-AMB 10

Despite the time pressures for rapid testing options, speed was not the most important factor for the research team. Because this application comes into direct contact with DNA, it is only possible with certain biocompatible materials.

The Imperial College team is using Figure 4® MED-AMB 10, a transparent amber material capable of meeting ISO 10993-5 & -10 standards for biocompatibility (cytotoxicity, sensitization and irritation)*, and that is sterilizable via autoclave. This material is used for the translucent microfluidic manifolds. “Figure 4 MED-AMB 10 has shown impressive biocompatibility for our PCR reactions,” says Cavuto. “A lot of materials we’ve tried in the past have inhibited them, but Figure 4 MED-AMB 10 has shown low interaction with our reaction chemistry.” This is critical to the entire project, as any interference by the production materials could delay or prevent the intended reaction from happening.

Using Figure 4’s diverse portfolio of materials

Not only is the team using Figure 4 MED-AMB 10 to print the microfluidic components for Lacewing, but they are also using Figure 4® PRO-BLK-10, a production-grade, rigid, heat-resistant material, for the device enclosure, and Figure 4® RUBBER-65A BLK, a newly released elastomeric material, for gaskets through the device.  One part of Lacewing is even made from Figure 4® FLEX-BLK 20, a material with the look and feel of production polypropylene.  Besides the electronics and some hardware, nearly the entire device is currently produced using the Figure 4 system.  

Fully cleaned and post-processed in under 20 minutes

A clean and smooth surface is critical to the final functionality of the Lacewing cartridges. For this reason, the research team is foregoing any nesting or stacking capabilities of Figure 4 to print the cartridges in single layers. As the project is still in the design phase, the team has not yet fully loaded the build plate, but estimates a maximum build of approximately thirty microfluidic cartridges at a time.

Given the sensitivities of the application, post-processing is critical. Once printed, parts are washed in an IPA bath, cured, sanded, and washed again to ensure the parts are all free and clear of residue or sanding particles. “We want to avoid contamination at all costs,” says Cavuto. “Making sure the parts are clean and sterilized is important for a successful reaction and accurate diagnosis.”

In total, Cavuto estimates that post-processing takes under twenty minutes, and many parts can go through the process at once.

Rapid diagnostics device developed using Figure 4 technology at Imperial College London

New capabilities for development and innovation

“Figure 4 has changed what I can print, or what I think I have the capability of creating,” says Cavuto. “In terms of resolution, speed, surface quality, range of materials, and biocompatibility, there’s nothing that compares to Figure 4, and I’ve probably used every type of 3D printer you can imagine.”

The Imperial College research team plans to have the COVID-19 test validated soon with the United Kingdom National Health Service (NHS), paving the way for scaled production within the next six months. For a complete look at how Lacewing works, explore this information page by the Imperial College research team.

BOA Dials In to Better Performance Fit Systems with Figure 4 Parts

Product: DLP Printing
Industry: Consumer Products and Retail

Whether they realize it or not, over half of the cyclists in the Tour de France rely on the BOA® Fit System as they churn out mile after mile on the course. BOA is also the common thread that connects workwear, medical bracing, and sports like golf, snowboarding, and trail running – as each integrates BOA’s patented three-part fit system into high-performance products, keeping workers and athletes dialed in.

The BOA Fit System is incorporated into the products of market-leading brands across industries that partner with BOA to give their users the best in performance. Available in a range of power levels designed to match the intensity of the sport and closure force needed for the product, BOA’s performance systems are designed to deliver a fast, effortless, precision fit.

The hunt for functional 3D printed materials

One of the main components of the BOA Fit System is the dial. The dials are engineered to three different power levels depending on the lace tensions achieved by the gear they are fitted to. This includes the high power snowboard dials with gear reductions for high torque that launched BOA’s success in 2001. Daniel Hipwood is a senior design engineer at BOA who spends his time working out the mechanical design for these products.

BOA has been using 3D printing to prototype for several years now, but according to Hipwood, it has been difficult to match BOA’s applications with the material performance they need. Because BOA’s products are small and mechanical properties are paramount, many 3D printing materials could only help BOA with concept verification and aesthetics.

“We’ve been really hamstrung by the materials available to us,” says Hipwood, explaining that the parts BOA was printing were turning brittle and not holding up over time. “We’d have a concept and three days later, if the part fell off a desk in a meeting, it would just shatter into a million pieces. It’s been a real challenge to find thermoplastic-like performance at the resolutions we need, and to actually 3D print parts that function at our scale and can still hold those properties.”

Although BOA’s workflow will still include small runs of pre-production injection molded parts for the foreseeable future, the company wanted to close the gap between 3D printed part durability and final injection molded parts so it could push its designs further, faster, and with greater confidence before beginning the tooling process. Its research led BOA to 3D Systems’ Figure 4 technology and materials.

Figure 4 3D printed part on fingertip

Taking testing farther with Figure 4

Figure 4 is a projection-based additive manufacturing technology that uses a non-contact membrane to combine accuracy and amazing detail fidelity with ultra-fast print speeds. Together with 3D Systems’ production-grade Figure 4 materials, BOA is able to use the Figure 4® Standalone to get early insights into production part performance. Rather than wait the typical three weeks for machined parts, BOA can now assess the viability of its designs in the same afternoon using Figure 4.

BOA uses several of 3D Systems’ Figure 4 materials, and is particularly fond of Figure 4® PRO-BLK 10. Unlike other additive materials BOA has tried in the past, this high precision, production-grade material has long-term environmental stability and thermoplastic-like behavior. This has proved highly beneficial and answered BOA’s search for a material that would deliver resolution and performance with the ability to hold its properties. The material is working exceedingly well for BOA’s purposes, and the company is conducting ongoing correlation tests between final production parts and Figure 4 parts to understand the threshold performance requirements it needs before moving on to production. “Sometimes it’s actually one-to-one, so they’re performing the same as our injection molded components,” says Hipwood.

As part of product development, BOA likes to take viable prototypes and get them on shoes early into the design process so testers can interact with them. Even for designs that will not go on to final production, attaching dials to shoes and putting them through routine abuse helps BOA gather design and performance data on what works and what doesn’t. This aspect of testing requires the dials to be sewn directly into fabric without molded holes. According to Hipwood, finding conventional plastics that can be stitched is difficult enough, let alone finding a UV cured material that will perform without cracking. “Punching a needle through plastic is a toughness problem. You need a material that is resilient, but still maintains enough stiffness to carry out its other uses. Part count reduction is key, so that stitched component may have other important functions that require a stiff plastic material,” says Hipwood. The fact that Figure 4 PRO-BLK 10 can be used to prototype in this manner has been a major help to BOA, saving time and money to quickly iterate its designs for the highest performance.

Along with its fit system, BOA is known for its lifetime warranty: The BOA Guarantee. Product quality out of the gate is paramount and having functional printed parts helps Hipwood and the team of engineers at BOA deliver new innovative products with faster design cycles and less redesign of components after tooling creation. “Everyone is striving to shrink and optimize their products, which makes it critical to identify the weak spots as early in the design process as possible to avoid finding problems when molds have already been created.”

Additional materials in use at BOA include Figure 4® TOUGH-GRY 15, a durable gray prototyping material, and Figure 4® ELAST-BLK 10, an elastomeric prototyping material. Beyond the small mechanical parts inside the lacing dial systems, BOA uses the Figure 4 Standalone to print aesthetic proofs of concept, end-use fixturing, and rubber-grip overmolds.

A track record of success

According to Hipwood, BOA’s decision to invest in 3D Systems’ technology was twofold. The first factor was BOA’s positive experience talking with the 3D Systems team, and the level of support and expertise 3D Systems demonstrated. The second factor was 3D Systems’ track record. As the originator of the 3D printing industry with an established and robust portfolio, BOA was confident in the longevity of its investment if it worked with 3D Systems. “Other options we explored felt kind of like an alpha or beta product that wasn’t quite tested,” says Hipwood. 3D Systems’ clear focus on innovation and advancing the state of additive manufacturing made the company stand out.

BOA is happy with its decision to bring Figure 4 onboard. “There are more than a few people here who can speak to how the printer is helping them validate their work,” says Hipwood.