PrintIn the rapidly advancing field of medical device manufacturing, engineers working in micro molding and plastic injection molding are pushing the limits of technology to meet the growing demand for smaller, more intricate devices. During a recent LinkedIn Live with Accumol’d own Craig Tappe and Jeff Dirkx, they explored the technical challenges working with delicate substrates, ultra-thin walls, and complex overmolding processes.
During the discussion, Dirkx highlighted one of the most difficult substrates to work with: gold-plated components. “Nothing sticks to gold,” Dirkx said, “It’s really hard to seal against that. So that has to be a consideration if we have an exposed gold surface in the electronics.” Thermoplastics and adhesives struggle to bond with the material, making it challenging to create reliable seals in medical devices with exposed gold surfaces. To overcome this, manufacturers often turn to elastomers, which can form seals around gold, protecting sensitive electronics from moisture.
Another significant challenge discussed was the overmolding of delicate components such as tiny wires. Dirkx described working with wires as thin as 200 microns in diameter, noting that the difficulty lies in securing them within the mold during the plastic injection process. “We had a customer with a few really sensitive components where we had to shift our gates around to keep them from getting damaged, but we’ve always found supporting those components and locking them into the mold to support them is absolutely critical.” he explained. This emphases the precision needed to avoid damaging the wires while overmolding.
The conversation also addressed the limits of miniaturization in molding, with wall thicknesses as thin as 0.002 inches being successfully achieved. “We’ve molded sharp points on things as well, so we can go extremely thin, extremely small. Materials, polycarbonates, polypropylenes. [We] mold a lot of LSR, which probably gives you the most capability when it comes to thin features. But LCP is very common.” Craig said.
High-flow materials such as liquid crystal polymers (LCPs) and medical-grade polymers are also frequently used for their ability to maintain structural integrity while accommodating intricate designs.
The discussion concluded by emphasizing the importance of collaboration and a holistic design approach. Dirkx noted that the design for manufacturability (DFM) team often looks beyond individual components to examine the entire device, leading to innovative solutions that enhance both manufacturability and functionality. “One thing The DFM team has done is not just looked at the single component, but taken on the whole device if allowed by our customers to look at the whole device and how the different components are interacting and come up with creative solutions for not just manufacturability, but even functionality,” he said, underscoring the value of cross-functional expertise in overcoming the complexities of modern medical device manufacturing.
As engineers continue to navigate these challenges, material selection, precision in molding, and a collaborative approach remain crucial in shaping the future of medical technology.