A pacemaker was not an option.

For that he was certain, even as dozens of doubts and questions swirled inside his head. The queries replayed endlessly in Robert’s mind as he lay in his hospital bed, connected to tubes for both hydration and oxygenation: Would his life be the same? Could he work again? Would he want to work again? Would he recover quickly? Was this medical emergency somehow his fault? And, would he have to give up running?

The answer to that last question was irrelevant, actually. Robert had no intention of abandoning his passion. He was a state and national championship runner, after all, who averaged 40-45 miles a week. Running had become more than a hobby to Robert—it was his stress reliever, his full-body rejuvenator, his source of contentment. It was part of his identity.

Robert was not about to give up such an important piece of himself.

“He needs to run, it’s in his blood,” Robert’s wife Maryse said in an online video. “You can’t change that.”

Can’t? More like won’t: When stricken with complete heart block a half-dozen years ago, Robert rebuffed any treatment that would compromise his ability to run.

Third-degree heart block (a.k.a., third-degree atrioventricular block) is a potentially life-threatening condition stemming from the blockage/interruption of the heart’s electrical signals. The disruption can cause the heart to slow down or stop entirely, and requires immediate intervention to restore proper function. The condition typically is treated with a pacemaker (temporary or permanent).
Robert, however, refused to consider such a remedy.

“When the doctor told me, ‘I suggest you put a pacemaker in your heart,’ I said, ‘no, no, I don’t need that, it’s not me. I’m in good condition, there’s no reason why I should put that thing in my heart,’” Robert recalled.
Turns out, Robert was partly correct. Since his heart’s electrical signals malfunctioned intermittently, there was no medically valid reason to fix the problem with a conventional pacemaker. So Robert’s cardiologist suggested he consider a leadless pacemaker.

“The doctor explained to me it was a little device, nobody would see it, that it would go inside my heart, and it’s not a long operation,” Robert said. “When he said I’ll be able to run, my heart rate went up and I said, ‘oh!’”

Upon learning he could continue running, Robert—not surprisingly—consented to undergoing an implantation procedure with Medtronic’s Micra, the world’s smallest pacemaker. It is one-tenth the size of typical pacemakers, measuring just 24 millimeters in length and less than one cubic centimeter in volume. Unlike its more traditional cohorts, the leadless device can be implanted directly into the heart and runs on a battery that lasts between 16 and 17 years, according to Medtronic.

Approved by the U.S. Food and Drug Administration (FDA) in April 2016, Micra was a byproduct of Medtronic’s “deep miniaturization” program—a decade-long effort to shrink medical devices by up to 90%. The program and its results are indicative of the growing demand for minimally invasive curative and diagnostic procedures as well as smaller medical devices with thinner walls and tighter tolerances.

Producing such miniature devices and components would be impossible without micromolding, a technology that efficiently and cost-effectively produces tiny, complex, feature-rich components. Micromolding can create parts that weigh a fraction of a gram or as small as a single pellet.

Or, in Micra’s case, the size of a vitamin capsule.

“We are looking at the beginning of the future,” cardiologist John Hummel, M.D., said upon the Micra’s FDA approval.

Medical Product Outsourcing consulted various experts over the last several weeks to peek into that future and better understand the market forces shaping the micromolding sector. Insight came from:

• Donna Bibber, CEO, and Brent Hahn, vice president of Business Development & Strategy at Isometric Micro Molding Inc., a vertically integrated micromolding company based in New Richmond, Wis.
• Katie Carmine, project coordinator; Cheyenne Frost, account manager; Patrick Haney, R&D engineer; Gary Hulecki, CEO; Dave Klein, process engineer; and Lindsay Mann, sales/marketing director; at MTD Micro Molding, a Charleton, Mass.-based micro medical manufacturer of ultra-precision molded components.
• Scott Herbert, founder and president of Rapidwerks Inc., a Pleasanton, Calif.-based precision micromolder.
• Vijay Kudchadkar, director of advanced engineering at Westfall Technik Inc., a global holding company providing plastic part manufacturing solutions for the medical, packaging, and consumer goods industries.
• Brett Lenz, engineering director at Scottsdale, Ariz.-headquartered Plastic Design Company, a specialty manufacturer focused on precision injection molding and value-added assembly for medical device and life science customers.
• Paul Runyan, vice president of sales at Accumold, a high-tech manufacturer of precision micro, small, and lead frame injection-molded plastic components based in Ankeny, Iowa.
• Raghu Vadlamudi, chief research and technology director at Donatelle, a New Brighton, Minn.-based firm providing medical device design, development, and contract manufacturing services.

Michael Barbella: What trends are currently driving innovation in micromolding?

Donna Bibber: Every micro molding project seems to have innovation driving it. There’s some level of complexity and challenge that requires ingenuity of highly skilled tooling designers and fabricators, process engineers, and quality engineers to set the stage for mitigating risk. The targeted trends are high aspect ratio cannulas, sheaths, catheter tips, and robotic surgery end effectors. These long and thin components and assemblies are also getting more sophisticated with the addition of smart sensors and electro-mechanical functionality added to them, requiring even thinner walls and precise sensor placement.

Patrick Haney: There is a drive to streamline assembly processes to reduce secondary operations in order to save cost and improve yield and quality. We continue to see the trend where teams behind the design of miniature assemblies are trying to find ways to decrease the amount of steps needed to yield a final, high-quality product. This is something that comes up earlier in project conversations than in the past and we discuss these opportunities as early as in the prototyping stage. Customers want to know what is possible now and later with their micromolding partner to avoid having to add additional vendors for their program downstream.
Scott Herbert: We are seeing a surge in applications in that demand higher detail with regards to small features.

Vijay Kudchadkar: In pursuit of enhanced quality of life and patient well-being, medical device manufacturers are vigorously advancing miniaturization boundaries. Achieving sub-0.001g weight for injection molded components and sub-0.002” wall thickness, these trends align with cost-effectiveness aspirations for broader global accessibility. To address these miniaturization requisites, contract-manufacturers like Westfall are pioneering novel technologies and leveraging cutting-edge methods for mass-producing micro parts with elevated efficiency. Micro molding innovation encompasses eliminating cold runners, deploying high pressure and mold temperature for filling thinner wall sections, and streamlining micro assemblies via multi-shot molding and allied advancements. These endeavors collectively meet the growing demands of miniaturization while ensuring optimal production yields.

Brett Lenz: We deal with micromolding projects in general from a few different industries, all medical. They all have their own trends somewhat separate of each other. Our product segments are roughly evenly split between medical devices with micromolding and micro on macro-type products such as microfluidics, small features on larger footprint parts.

In the micro-on-macro realm, a lot of the development we see is around different types of fluidic geometries and what you can do with those; getting sizes down, getting smaller and smaller channels —those are kind of the obvious ones there. Maybe a little less obvious as a challenge for molding specifically is looking at features that have high aspect ratios—very thin features that are also quite deep or tall, think a flat plate and how deep those channels go into that plate, that becomes a real challenge when you get into that small scale, just for the integrity of the molding features and the tool.  

On the flip side, going back to other medical devices and pure micromolding, the obvious major trend is miniaturization of almost everything. Smaller features, smaller parts, and tighter tolerances is always the name of the game. There again we’re looking at what’s feasible with tooling and the different materials that are out there. A lot of what we see is really looking to push the boundaries of what would be normal feasibility considerations with parts like that. How can we manage to work with even less draft so we can maintain a consistent diameter over a longer stretch? How can we deal with complex geometry for side coring that enables all kinds of different functionalities on those types of devices. That’s a lot of what we’re looking at.

On the bigger picture project management side we see a push for rapid prototyping, in particular prototyping that’s relevant to molding. That’s actually a new capability we’re really leaning into here—the fast-turn prototypes of molded parts. Not just 3D printing, not etching or machining prototypes but actual injection molded parts that we can take a design, get a prototype insert set made for and have parts in hand in just a week or two, given some design constraints to make that work for feasibility. That’s probably the biggest push we’ve seen recently is the drive for fast-turn prototyping in injection molding. Why that’s so important for injection molding specifically? It probably really gets down to fear of prototyping through any one of those other processes; unless you’re working with a molder for your design feedback and input you may be missing a lot of good basic Design for Manufacturability practices like draft, wall thicknesses, ability to fill, shrinkage—those types of things—even down to simple items like gate location or ejection. Design elements that are going to be characteristic of what you’re going to have in a scaled injection mold process when you’re well past the prototyping stage. If you can be tackling those things during your prototype stage you’re set up for success that much more. If we can identify ‘where are the limits of how flat we can keep this part’ or how good a feature replication we can achieve with an actual mold in the prototype stage, all the better.

Paul Runyan: Our customers drive our innovation road map. We only want to invest in new technologies if it is relevant to our strategic customers. Over the past six years we have been pushed to solve problems in the area of micro LSR over molding, light assembly of micro components that are then shipped to CMs or our medical device OEMs for final packaging/assembly, and we have just launched a new capability where we are now able to mold thin wall cannula’s for the drug delivery channel.

Raghu Vadlamudi: Notable trends propelling innovation in micromolding encompass:
Miniaturization: The demand for smaller and more intricate parts in industries such as electronics, medical devices and aerospace has driven the need for micromolding. This trend involves producing components with extremely small dimensions, high precision and tight tolerances.

Innovation in Materials: The development of new materials with improved properties, such as enhanced strength, biocompatibility, thermal resistance and electrical conductivity, has opened new possibilities for micromolding applications. The utilization of finer metal powders is unlocking the realm of heightened innovation in the micromolding industry.

Automation:  The integration of automation and robotics into micromolding operations has improved efficiency, minimized cycle times and increased consistency. Moreover, automation facilitates the fabrication of intricate components that pose challenges under manual methodologies.

Advanced Tooling and Process Control: Advancements in mold design, production and process control have led to greater precision, fewer defects and enhanced part quality. Hot-runner systems and in-mold sensors further enhance the monitoring and control of processes.

Barbella: How is your business (company) responding to these trends?

Bibber: While not all medical and drug delivery devices require micro molding, the most complex and enabling components are often the most challenging to supply and require the skillset and culture of micro molder.
Isometric has historically been early adopters of micro manufacturing technologies that help medical device OEMs get to the top of their respective value pyramids, which is platform enabling intellectual property.
Submicron capable tooling, CT scanning, micro molding, 3D micro printing, high speed automated nanoliter dispensing, and micro tensile polymer testing are capabilities developed based on Isometric’s customer needs.

Haney: In terms of materials from a micromolding standpoint, we see an increasing need for shape memory performance in part designs. This has driven new internal research and development activities to discover materials that are flexible with high processability for tiny geometries. Having an internal R&D department helps us move through unique and new customer requests as they arise. Most times, in parallel with full-scale production, we are working on R&D activities for that same program to reduce manufacturing steps, decrease cost, and improve functionality for scale-up projections.

Lindsay Mann: Building strong relationships within the various teams of our OEM customers is more important than ever as they are depending on their selected molder to take on more than just molding. Customers rely on MTD’s expertise to help with design optimization, assist with material selection, and incorporate automation and we understand the responsibility that comes with providing these recommendations.
Herbert: We have to invest in the future new technology, which will aid in fast turnaround and a quicker delivery of solutions.

Kudchadkar: Westfall has developed the world’s only micro molding solution that eliminates the need for cold runners to mass produce micro parts, resulting in over 50% reduction in piece price through decreased material consumption and faster cycle times. In partnership with top high pressure and high mold temperature solution suppliers, Westfall enables sub-25 micron wall section filling. Westfall’s vertically integrated approach to precision and micro tooling and molding has led to achieving CPK >1.33 for micro parts with sub-0.015 micron tolerances.

Lenz: We’re looking at each of these types of projects and we really take a pretty consistent approach to all of them. Every new project we look at start with a DFM review. We first try to understand what that part is being used for, what its core functionalities are and that helps us understand where those trends are and where they’re coming from. Then we use that to work through the engineering challenges behind that—what’s really important and critical to function for those things and what has some room for flexibility to maybe improve how robust that tooling project can be. We start with that, it’s a lot of upfront analysis, we’ll bring in finite element simulations (Moldflow) to help get some get some good early input before committing to tooling, where that’s appropriate. We’ll use that to assess that feasibility. We also try to be educators and help our customers understand what those challenges are. Help them walk the line between what is possible to do (your bleeding edge) versus what’s possible to qualify—what can you show, a statistically rigorous process around, and explore where those boundaries are and try to push them.

Runyan: Accumold has a culture of trying to solve our customers problems/concerns and a lot of good solutions come out of our DfMM sessions on the front end of project discussions. For Accumold, DfMM stands for Design for Micro Molding solutions and we have a real talented technical team that work closely with our customers engineers and designers. Micro LSR is a good example of this—we had a customer that wanted a problem solved with a very small LSR over molded part and they asked us to help. We also started to see a trend in the medical space where micro LSR was starting to be an opportunity where we felt we could compete.

Vadlamudi: As a contract manufacturer in the medical device industry, Donatelle responds to the above trends by adapting its processes, technologies and strategies to meet the evolving needs and demands of its customers. We invest in advanced micromolding equipment and precision tooling to produce smaller and more intricate medical device components with high precision and tight tolerances. Donatelle collaborates with material suppliers and stays updated on the latest advancements in biocompatible and high-performance materials, allowing them to offer a wider range of material options to our customers. Donatelle also implements automation and robotic systems into its micromolding processes to improve efficiency, reduce labor costs and ensure consistent quality for high-volume production. Donatelle employs highly skilled people in advanced mold design and fabrication techniques who are well versed in utilizing in-mold sensors and real-time monitoring systems, to ensure precise control over the micromolding process and minimize defects.

Furthermore, our commitment involves ongoing research and development to anticipate emerging trends, alongside providing design for manufacturability (DFM) expertise to our customers. We nurture close partnerships, prioritizing the fulfillment of unique needs and demands. It’s pivotal to acknowledge the medical device domain operates within stringent regulations. Donatelle diligently adheres to pertinent quality benchmarks and regulatory directives, including ISO 13485 and FDA mandates.

Barbella: What do OEMs look for when choosing a micromolder? Why would an OEM choose your company?

Brent Hahn: OEMS are looking for a micromolder typically in one of three ways: 1) They’ve received no-quotes from their current macro molders on their approved supplier list, 2) The macro molder failed, or 3) The OEM has gained experience realizing that components and/or assemblies of a certain difficulty or complexity require a partner that specializes in these challenges. Typically, micro-size parts or larger components with micro features, thin walls, complex geometries, tight tolerances, or a combination. OEMs should choose Isometric Micro Molding first and foremost because of our people, our subject matter expertise, and our culture of Microns Matter.® Over the last 33 years and over 1,000 miniaturization-focused projects we are experts in DfM and DfA and help OEMs quickly create scalable manufacturing solutions to support fast to market product launches.

Gary Hulecki: Medical OEMs are no longer looking for suppliers. They are seeking partnerships where they have strong, lasting relationships where both parties help each other move through a project as quickly as possibly with the highest quality result. We have changed the way we do business significantly based on this.

Haney: We have as much mold making expertise as we do plastics processing expertise. We design program solutions from the ground-up and during development if issues arise, we address them quickly and efficiently in-house. Turnaround from molding room to machine room is minutes, which is huge benefits for our customers.

Katie Carmine: It seems these days that they are looking for a micromolder that will provide more services than just molding – testing, packaging options for example.  They are looking for a partner who will collaborate with them to solve problems that arise during their project and be flexible with changes and requests as they come.  We are seeing more and more customers looking for MTD to guide them through the development process as well. Our team cares about our customers and doing whatever we can to help them achieve their goals.

Cheyenne Frost: Medical OEMs tend to look for a supplier that can handle all aspects of the manufacturing process for their device. OEMs choose MTD because of how specialized our technology is, the confidence we provide, and the need for a truly complex micro molded device. MTD can move quickly with requests and communication, which can help improve project lead times.

Herbert: OEMs look for experience, contact with key personal that know the technology and understand how to articulate the technology to the designer to help aid in the process of design for success in manufacturing.
Kudchadkar: At the core of micro molding lies precise micro tooling. With 59 years of experience, Westfall’s Twin Cities tooling site (formerly Mold-craft) excels in crafting high-quality micro part tooling. Westfall’s exclusive M3 eliminates runners, and we leverage Sodick and Wittmann platforms as needed. Collaborating with the best high mold temperature solution providers, Westfall’s adept engineering team passionately pushes micro tooling and molding limits. This empowers OEMs to realize their miniaturization and cost targets effectively. OEMs also pursue micro molders possessing substantial expertise in Bioreabsorbable micro molding and PEEK micro molding for implantable applications. Westfall has significant experience in a variety of micro molding applications.

Lenz: There is a plethora of reasons. Number one is they need someone they can trust to work with. They need someone they know will give them the quality product they’re looking for, particularly in the medical arena—that’s paramount. Good assurances that you’re going to get good quality products, you’re going to get good support from a robust quality system that’s going to maintain the traceability, the specification demands of their part, and someone that’s going to be around to maintain all those records. As their product goes to market they want to have the support of that traceability chain all the way through. Beyond that, what’s the technical capability? Folks are out there trying to push the limit and trying to be the next best thing out there in whatever particular niche of the industry they’re in and we want to support that. Why would someone come to us for that? That’s what we’ve been doing for 30 years. Our forte is taking projects that are early in their feasibility and their testing phases and helping them scale up to large production settings and all the steps in between. Getting through testing, helping nudge that part design to a good robust state that’s well-suited for large scale production molding. Helping navigate through often arduous validation protocols, making sure we have statistical controls and confidence that the part is reliable and can run in a reliable production setting. That’s who we are, that’s what we have a long track record of doing.

Runyan: We love when customers or prospects come to Accumold for a site visit.  Again, most are looking for a company that has scalability, capability, and sustainability.  Our visitors compliment us on how clean our factory is—we have nine clean rooms (three Class 7 and six Class 8 rooms), we have a deep bench of very talented skilled employees who have longevity with our company, and our customers like that our team works hard offering our “micro solutions for their big innovations.”

Vadlamudi: OEMs seek out micromolders boasting a well-established history of proficiency and experience in micromolding. They prioritize a demonstrated capacity for reliably crafting top-tier micro parts with meticulous accuracy and uniformity. OEMs critically evaluate the micromolder’s readiness to navigate micromolding intricacies, encompassing specialized equipment, cutting-edge technology and adept process control techniques. Furthermore, OEMs demand a collaborator equipped with robust material knowledge to optimize designs for consistent manufacturability and uninterrupted supply, all while ensuring alignment with rigorous regulatory mandates.

In this context, Donatelle emerges as a distinctive partner, exclusively serving the medical device sector. This focused dedication has enabled the cultivation of a mature quality system, adept at facilitating the development of Class I, Class II, and Class III devices. Donatelle’s specialization lies in the production of medical industry components, including precision micromolded parts. With Donatelle’s expertise in scientific molding along with in-house mold building capabilities and the knowledge of implantable materials, we are an obvious choice for many OEMs in manufacturing their micro parts.  Donatelle has extensive experience in molding PEEK, the popular choice for small parts. Donatelle has the equipment and capabilities slated for micromolding and have been providing those services for over 50 years.

The company’s adeptness guarantees adherence to medical device regulations, biocompatibility norms and sector-specific requisites. Donatelle’s comprehensive offerings span the gamut from design and prototyping to manufacturing and assembly, streamlining the supply chain and affording OEMs the opportunity to channel their energies toward core competencies.

Barbella: How does micro-level material behavior impact device design and performance, and how does it differ from macro-level material behavior?

Hahn: Micro molding parts with wall thicknesses of 0.001” seemed nearly impossible just a few years ago. With miniaturization becoming more prevalent in medical devices and other high precision industries, micro molding high aspect ratio up to 400:1 creating incredibly thin wall parts and feature sizes down to 3 microns are now possible. For example, a 0.007” wall thickness PEEK stent was originally deemed impossible by resin experts who recommended nothing less than 0.020” thick. Molding 3-micron needle sharps without flash is also pushing the boundaries of material behavior at the micro scale. The proof lies in Isometric’s internally developed micro tensile bars of 0.001” (25 microns) to 0.015” (375 microns) part thickness and two gate types to determine the ability to fill, actual shrink rates, and gate vestige.

Haney: Types of defects can form in a micro part that would not form in a macro part due to the nature of the size. For example, micro shapes greatly limit material options and are more prone to molding defects if not processed correctly. The effects of the micro environment need to be understood to correctly predict what a molding process will look like. On the micro level, predictable behavior stops and simulation and conventional viscosity equations no longer represent what could happen during molding.

Dave Klein: Micro injected parts can be difficult to fill with thin-walled or relatively long flow lengths vs. part thickness. When injected, micro-level material can see extreme pressures and shear that find the limit to viscosity reduction. Minimal part thickness creates situations where gate freeze time is almost negligible. These two characteristics make part design and gating locations extremely important. On the macro scale, parts can be designed with additional supporting features or gate locations for aesthetic reasons that may not fill in the micro scale.

Kudchadkar: Micro molding requires substantially elevated shear rates compared to traditional molding, profoundly impacting material viscosity. The process demands markedly higher injection pressures, with material solidification and shrinkage intricately tied to pressure—higher pressure correlating with heightened solidification temperatures. Solidification time is notably contingent on wall thickness. Given the considerable variation in wall sections within micro molding, issues may arise such as premature solidification or insufficient packing in thicker segments, consequently leading to undue material shrinkage.

Lenz: That’s a really good question, it’s a bit of a rabbit hole. When you get into small cross sections the material flow behaves very differently. If think of molten resin flowing into a mold cavityin a larger part,  anywhere that flow front touches the cavity walls or even touches the air in front of it you’ll get some cooling right there. There’s a thermal transition and that usually results in having a frozen skin surrounding the melt flow as it moves in. While not a perfect analogy, you can think of it like watching a lava flow out of a volcano. You see this crust on top and then there’s this hot flow beneath it pushing it forward. A similar thing happens in a mold. In a larger part you have room for all of that to exist. You have that frozen skin on the outside and on the surfaces surrounding the flow, and then you have a molten core that pushes through and flows through the cavity. That molten core is then very important to maintain even once you get the part filled, you’ve gotten flow to all the areas of your cavity, you then have a pack cycle. You keep with pressure forcing more molten resin to bring the density up to where it needs to be because as the resin cools it will shrink and you want to compensate for that by making sure have proper density throughout the cavity. If you have areas that have already frozen off completely you’re not pushing this kind of semi-viscous flow anymore, you’re pushing what’s effectively a solid. You can’t pack any more material into that space without remelting or having other ways of doing that.

Now when we take the scale way down, we can actually get so thin that everywhere is frozen skin and what you’re actually doing is not pushing a molten center and expanding that skin so to speak, you’re just pushing a cold front through a really thin cross section and that’s sometimes what you have to battle with micromolding. What can happen there is as you keep applying pressure you get really high sheer stresses on the material and you can reheat the material through sheer and that throws your traditional processing understanding right out the window. You’re essentially remelting the material constantly as it flows into different areas of your cavity. That’s where simulation can help you see where that might happen and predict issues you might have because of it. You can sometimes see evidence of that in the parts themselves through different types of flow lines,stress cracking, or warp. You can sometimes highlight where those phenomena are happening. It’s quite a deep analytical challenge to really dive into that and understand what’s going on and then make recommendations to your customer.Of course, there’s lots of things you can explore with mold processing even at that scale sometimes surface finish can come into play and helping attack some of those problems.

Thermal control is kind of an interesting one we see in microfluidic arena specifically. Wall sections are relatively thin—anywhere in the 1mm-1.5mm range is quite common. But on larger footprint parts we’ll see common SBS format size, roughly the size of an index card. At those thin wall sections you get this early freeze-off phenomena, and you lose your molten center that you have for your melt flow. By the time you get to the extent of the cavity what ends up happening is you’re only able to pack out certain areas of that part to different levels. Since you have a variation in pack density throughout the part, that manifests as a variation in how the part shrinks. Very near your gates you might have relatively low shrinkage and very far away from your gates you might have much higher shrinkage rates. In the most extreme cases there’s really not much you can do about that with traditional injection molding. There’s injection compression, which is a whole other animal. It’s well-suited to deal with that but it has its own trade-offs. To deal with this in traditional injection molding a technique we’ve adopted is to actually compensate for the variable shrinkage in the tool design. We’ll empirically determine what that shrinkage variation is, say in a prototype tool. Then we have a nice data set we can go take measurements and figure out for that specific geometry what shrinkage rates we’re getting, reverse engineer that and apply that variable shrinkage rate to the next iteration of that tooling. It’s a really advanced process that we use to basically help us adapt to the limitations of molding in the micro world.

Runyan: Material selection alone can have a profound effect on feature performances. Design and aspect ratios are also important to consider for being successful in any micro component project. Material choice is a critical factor in thin wall applications and we published a “Thin Wall White Paper” 15 years ago where we built a tool to see how far we could mold a 0.003” thin wall using 11 different resins. We found we could get four resins to go 42 to 1 aspect ratio to the end of the thin wall part.

Vadlamudi: The surface-to-volume ratio, failure mechanisms and multi-physical behavior of micromolded parts hold utmost importance in shaping device design and performance. At the micro-level, surface effects become more significant, influencing attributes like strength, wear resistance and frictional characteristics. This is due to the notably increased surface-to-volume ratio in comparison to macro-level counterparts.
Additionally, the micro scale accentuates adhesion and chemical reactivity. Material behavior at this scale is marked by distinct multi-physical traits, leading to varying material hardness based on composition and structure. Micro cracking and fatigue failure are more prevalent as failure mechanisms. Micromolded parts exhibit notable variations in electrical and thermal properties, which can significantly impact device performance. Manufacturing at this scale introduces an added layer of variability tied to processes and defects, thereby influencing long-term stability and device performance. On a contrasting note, the micro-level offers expanded avenues for design innovation, particularly in the realm of miniaturization and wearable devices.