Shrinking Medical Devices Create Sizable Challenges for Micromolders

Timing truly is central to business success.
 
Microsoft, for example, could very well have been the world’s first trillion-dollar company had the public warmed to its tablet at the millennium’s dawning. Similarly, the world was not quite ready to embrace the future when Bell Labs unveiled its Picturephone in 1964 (imagine how different life would be today had it become commonplace back then).
 
Surprisingly, biotechnology firm Vaxxas hasn’t encountered that same dead end despite its invention being a bit ahead of its own time. The privately-held company is developing needle-free vaccination technology originally hatched by the Australian Institute of Bioengineering & Nanotechnology at The University of Queensland.
 
The technology uses a proprietary high-density micro-projection array patch (HD-MAP) to streamline and improve vaccine delivery. The postage stamp-sized silicon patch contains tens of thousands of projections 200-300 microns in length that release vaccine antigens directly to immune cells sitting just below the skin’s surface.
 
Preclinical studies have shown the Nanopatch to be considerably more effective than conventional vaccine delivery systems, with as little as 1/100th of its dose eliciting the same immune response as a “full” portion through intramuscular injection. Moreover, Nanopatch’s dry-coating technology eliminates the need for vaccine refrigeration during storage and transportation, thereby eliminating the resource burden of maintaining a cold chain.
 
“Based on our results, we believe that Vaxxas’ HD-MAP could offer a compelling solution that importantly could use less vaccine and potentially could be readily distributed without refrigeration for self-administration,” David A. Muller, Advance Queensland Industry Research Fellow, School of Chemistry and Molecular Biosciences, The University of Queensland, said last June. “This combination could make the HD-MAP extremely well suited to support the massive need for global population vaccination and indeed, we believe that HD-MAP offers a superior alternative to conventional needle-and-syringe.”
 
That superiority lies in the microscopic projections responsible for delivering vaccines. Those projections likely were created through micromolding, a highly specialized manufacturing process that produces extremely small, high-precision thermoplastic components with micron tolerances. This technique has become integral to medical device manufacturing of late as devices continue to shrink in size and scale. 
 
MPO’s feature “Big Shots” details the trends and market forces driving micromolding in the medical device industry. Aaron Johnson, vice president of marketing and customer strategy at Accumold, was among the more than one dozen experts interviewed for the feature. His full input is provided in the following Q&A:
 
Michael Barbella: What are the latest trends in micromolding technology and services? 
Aaron Johnson: Traditional tool building for short-run prototype parts can be prohibitive by speed and cost. New developments with 3D printing, like with Fabrica Group’s high precision Fabrica 2.0 printer, can complement micromolded R&D efforts and help get new products to market faster.
 
Barbella: What are customers demanding or expecting of their micromolded products and have these demands/expectations changed in recent years?
Johnson: Speed to market has long been a desire of the industry. Competitive pressure, even in the medical device industry, is also a key driver for many OEMs. The continued growth towards miniaturization has only increased this demand. And of course, quality expectations are never less than perfect.
 
Barbella: How have advances in materials impacted micromolding technology? 
Johnson: Accumold is fortunate to have great resin partners. We are often asked to beta test new materials to see how they perform in the micromolding arena. Manufacturers continue to want smaller and smaller components. This drive has pressured the resin industry to develop materials that can withstand different manufacturing environments, like 3x solder reflow, while maintaining the integrity of the material. This also must be balanced with resins that are good candidates for micromolding and micro features.
 
Barbella: Please discuss the challenges and complexities involved in micromolding tooling design. How can these challenges be overcome?
Johnson: Nothing is as simple as it seems, especially with micromolding. The smaller, more complex, or the tighter the tolerances the greater the challenge can be for tool design and processing. At Accumold, we walk each project through our DfMM—design for micromolding—process. It’s a must for any micromolding project to be successful.
 
Barbella: Design for Manufacturability is critically important in micromolding. How is this different than conventional DfM?
Johnson: Accumold takes the DfM process one step further—DfMM—design for micromolding. We recognize that when designing micro parts or components there can be many roadblocks on the path to success. Some of these can be as simple as finding a gate location. Molding a micro part that is only a millimeter or so in size can limit where or how a part can be gated. Material selection can also add to the complexity. Not all materials are a fit for small features, thin-wall sections, or details. It is overcoming these types of challenges that experienced micromolders can bring to the table. 
 
Barbella: Are machine learning and AI playing a role in medical device micromolding? If so, how?
Johnson: There is no doubt the medical device industry demands perfect parts every time, especially when it comes to critical components. Any technology that can add value to quality assurance favors a look. Machine learning and AI are quickly becoming an everyday part of in-line, automated inspections systems. Adding this type of technology on high-volume manufacturing cells can not only help ensure the customer’s quality requirements, but it can also help reduce costs and time to market efforts.
 
Barbella: Is there a limit to how small a micromolded part can be?  
Johnson: Sure, but I’m not sure we’ve hit that yet. One of the smallest parts a customer has asked us to produce has its longest dimension at only 800 microns. We’ve also produced features on micro parts that are sub-micron in size. Yes, there will be a limit but we’re always up for a challenge.
 
Barbella: What medtech speciality (cardiology, wearables, orthopedics, etc.) presents the greatest challenge in producing micromolded parts and why? Which present the greatest opportunity?
Johnson: Long-term implantable devices will remain the most challenging. Not so much for the parts themselves, though micro parts do bring their own complexities. The challenge can sometimes be the materials available for the geometry desired. Material selection and micro features have a profound relationship at the micro level. Implantable grade materials may not always be a good fit for the desired outcome.
The greatest opportunity comes as at-home/personal care services increase. Medical device wearables are a big leader in this demand but its not just fitness trackers, blood-glucose monitoring, or hearing aids—there are many other patient-centered technology uses on the rise. This demand often puts pressure on the supply chain since there is a common desire for these type devices to be as discreet as possible and/or disposable. This means the industry will be looking for high-quality, micro-sized components that meet cost and manufacturing requirements.
 
Barbella: What regulatory requirements/changes have impacted medtech micromolding and how?
Johnson: Anyone working in the medtech space will eventually feel the regulatory impact on the industry, even if you’re a tier II or II supplier. And certainly, the closer you are to a finished good, the higher the impact. In addition, the recent changes to the ISO 13485 quality system management have challenged organizations to rise to the occasion as well. The process to be a qualified supplier to medtech companies is not getting easier. Today’s suppliers must have a robust QMS to meet the demand.
 
Barbella: How might the medtech micromolding industry evolve over the next five years?
Johnson: As the demand for medtech devices to do more in the same space, or more in less, increases, the interest in micromolding will follow accordingly. At the same time, the desire for OEMs to reduce the supply chain management costs will compete for attention. Those challenged with the design and development of next-generation products will have to navigate partners that can truly meet their needs. As nice as it would be, it’s doubtful a one-stop-shop can do it all. A careful selection of integrated partners, like a micromolder, will be needed.