Machining and laser processing are evolving fields in medical device manufacturing and continue to advance in programming, capabilities, and tolerances. As a result, these now-mature processes are highly specialized and tightly integrated into end-to-end medical device manufacturing and are a requirement for being competitive on cost. “CNC [computer numerical control] machining is essentially indispensable because it can reliably hold very tight tolerances across a wide range of implant and instrument materials,” said Joe Traverse, director of program management for Tegra Medical, a Franklin, Mass.-based end-to-end manufacturer of medical devices, including assembly, packaging, and sterilization. “Laser processing, including cutting, welding, and engraving, has become the default for fine features, thin-wall tubing, and intricate geometries in complex devices and assemblies.” 

Two key goals for all sectors of medical device design are miniaturization and automation. One of the hottest machining markets is robotic surgical equipment, which is projected to grow globally at a rate of 17% CAGR (compound annual growth rate) over the next several years.¹ This impressive growth is attributed to increased demand for minimally invasive surgeries (MIS), sophisticated robotic systems, hospital investments, and the rising cost of healthcare.

“Such intense demand for miniaturization and robotics then drives the need for smaller end-effectors and other components,” said Jeffrey Haag, vice president of technical solutions for Precera Medical, a Minneapolis, Minn.-based provider of precision machining and assembly for the medtech industry, including implants and MIS instruments. “Manufacturing teams then look for systems that can adapt to the challenges of machining, measuring, assembly, cleaning, and packaging for ever-smaller devices.”

Technology advances (especially for software and process control) have enabled medical manufacturing to move from steady, predictable production to responsive machining for small runs of unique part numbers. “Lot sizes are shrinking, devices are becoming more customized, and tolerances keep getting tighter,” said Michael Huggett, president and CEO for INDEX Corporation, a Noblesville, Ind.-based global provider of CNC turning machines. “Success now requires a marriage of flexibility and stability—switching over quickly, maintaining micron-level repeatability, and preserving profit margins, despite increased complexity.”

Ryan Poff, vice president of sales for John Evans’ Sons, a Lansdale, Pa.-based designer and manufacturer of precision-engineered springs, wire forms, and mechanical assemblies, agreed.

“The medical device industry continues to push machining toward tighter tolerances, smaller geometries, and higher levels of process control,” said Poff. “Precision machining now plays a critical role in producing reliable, repeatable components that meet stringent regulatory and performance requirements, especially as devices continue to miniaturize.” 

Recent machining and laser trends in medical devices have reduced risk from a process failure mode and effects analysis perspective by eliminating downstream processes. For example, lasers integrated with Swiss-style CNC machines provide burr-free cross-drilled holes, whereas traditional cross drilling mitigates burrs by using different combinations of brushes and/or abrasive blasting.

“Traditional machining has seen increased affinity for making parts from bar-fed machines,” said Mike Doyle, new product introduction manager for Cadence, a Staunton, Va.-based full-service, vertically integrated medical device contract manufacturer. “Coupled with computer-aided manufacturing [CAM] software, these programs include in-machining deburring cycles that help maintain higher Cpk [process capability index] values across all features where tumbling removes material from all exterior surfaces, increasing overall variation.”

Laser technology continues to see improvements in speed, accuracy, and dimensions. “Hot segments for lasers are robotic-assisted surgeries, pulse field ablation, and heart valves in the cardiovascular space,” said Skylar Scott, engineering manager for Resonetics, a Blain, Minn.-based provider of micro manufacturing services for the medical device industry, including laser processing, nitinol processing, and metal fabrication.

Picosecond and femtosecond lasers vaporize metal without the use of traditional assist gases such as oxygen or argon. For traditional lasers, pickling acids such as hydrofluoric acid are employed to erode stubborn laser slag; when this is not feasible, time-consuming abrasive blasting is used. “Both methods erode material features and surface finishes and may even require tertiary processes such as electropolishing to restore fine finish,” said Doyle. “From quality and cost perspectives, the statistical probability of non-conformance can be mitigated by eliminating secondary operation degradation.” 

Latest Trends 

The latest developments in machining and laser processing are all about precision, speed, and smart automation. “Customers are asking for tighter tolerances, micro features, and fully traceable manufacturing data,” said Poff. “This is especially true for medical devices, where miniaturization and materials demand cutting-edge solutions.”

Smaller parts require a different machining approach for not only machine selection, but also tooling design and spindles that can produce and sustain the higher RPMs needed to optimize cutting conditions for productivity and quality. As a result, gear-driven tool holders capable of 48,000 RPM for Swiss machining are becoming more prevalent. “Air-bearing spindles are also widely adopted for tooling applications below 3.0 mm in diameter,” said Haag. “Additionally, combining processes such as Swiss machining and laser cutting into a single machine platform for products such as hypo needles and small flexible tubular products allows for single-op processing with higher quality and throughput.”

Where machining and laser processing were once independent steps, “we now approach them as a single manufacturing strategy—machining, laser marking, surface finishing, and validation, all integrated into one workflow,” added Mike Couch, business development manager for Precision Medical Technologies, a Warsaw, Ind.-based provider of end-to-end solutions for orthopedic and MIS device design and manufacturing. “This approach allows medical device customers to bring products to market faster and reduce handoffs, scrap risk, and variation between supply stages.”

Medical device manufacturers (MDMs) continue to push for more customization and faster speeds. They seek machining processes that can run a broad range of part families and still consistently maintain high quality across all of them. “We’ve seen this reflected in increased demand for our Traub TNL Swiss-style machines,” said Huggett. “These blend the productivity of classic Swiss-style machines with the versatility and power of tool turrets, with a thermally stable foundation. Manufacturers can load up to 50 tools on these machines and consistently produce complex medical geometries. That level of configurability gives MDMs real agility—which is one of the greatest competitive advantages in medical device manufacturing.”

Even with these improvements, MDMs are still intent on designing smaller and more challenging devices with more functionality, which then requires contract manufacturers (CMs) to develop creative manufacturing solutions using existing technologies, while investing in new technologies such as femtosecond laser processing. “Automation of machining and laser processing is essential to be competitive with pricing, as MDMs are determined to increase throughput while still reducing piece price,” said Traverse.

What MDMs Want

Miniaturization is the go-to objective for MDMs. “As MDMs design new MIS products, they rely on process subject matter experts [SMEs] within their supply chains to provide feedback and guidance in early designs and prototypes to make sure the best cost solution is achieved early in the development cycle,” said Haag. “These SMEs continue to lean on the latest industry technologies for machining, laser processing, and metrology solutions.”

Welded assemblies, especially smaller ones, require very good fit and form between the two or more mating parts. This often requires holding tolerances tighter than the finished product needs, just to achieve good weld integrity. Even small changes in the edge condition of the respective parts can play a big role in the consistency and integrity of the welds part-to-part. “And, as parts get smaller, the challenges with inspection, cleaning, work holding, and automation get more complex,” said Haag.

According to Traverse, top requests from MDMs are:

• Smaller, more complex parts with tighter tolerances for minimally invasive devices
• Expertise in challenging materials such as nitinol, titanium, cobalt-chrome, high-performance polymers, and hybrids (for metal-polymer assemblies)
• Design for manufacturability and value engineering for deciding when to use machining or lasers (or both) to reduce secondary operations, improve yield, and control cost
• Turnkey prototype-to-production capability with validated processes, automation, and documented traceability that meet ISO 13485 and FDA expectations

MDMs are also asking for precision, customization, and reliability. “This includes tight tolerances, consistent repeatability across production volumes, support for miniaturized components, and manufacturing processes that align with medical and regulatory requirements,” said Poff.

“Overall, what used to be considered advanced is now a baseline expectation,” said Couch. “MDM partners are pushing for faster development cycles, extreme precision, and streamlined ramp-to-production pathways.”

One way MDMs can speed up development, shorten time to market, and reduce costs is by diversifying their product lines. “Dual sourcing of key components and sub-assemblies is happening more often for laser-processed and machined goods, and of course, cost-down initiatives are always at the top of everyone’s list,” said Scott. “We have seen multi-year cost-down commitments, as well as understanding how to incorporate higher volumes with lower costs in areas like Costa Rica. MDMs are attempting to pull faster timelines to get to the market first—it seems the entire industry is moving faster each day.”

Ultimately, MDMs want high-value manufacturing partners that have solutions for their toughest design and material challenges.

“Talent is scarce,” said Huggett. “Process engineers are overloaded. MDMs usually do not have the internal resources to pursue continual cycle-time reductions, validate new production methods, or support complex changeovers. CMs act as an extension of their engineering departments, validating processes and giving them versatility, without having to build and maintain a full in-house team.”

Technology Advancements 

Micro machining has become indispensable in serving the medical device industry. These technologies allow MDMs to achieve micro precision and deliver burrfree, compliant components. “By integrating custom equipment and advanced inspection systems, we are able to meet MDM demands for miniaturization, reliability, and scalability in critical medical applications,” said Poff.

Laser machining and micro machining have effectively become core capabilities for CMs. Micro laser processes (e.g., cutting, drilling, ablation, welding, and marking) are typically used to produce stents, catheter components, hypotubes, and implants with complex longitudinal geometries and extremely fine features. 

“Micro machining on ultra-precise CNC platforms handles features such as miniature threads, pockets, and transitions in metals and high-performance polymers with micrometer-level tolerances,” said Traverse.

Advanced lasers, such as femtosecond lasers, can drill holes in stainless steel below 25 µm (0.001 in) with some as low as 0.5 µm (20 millionths of an inch). “The advancement in lasers is so profound that we have yet to fully understand the design potential,” said Tony Pelke, director of manufacturing technology for Cadence. “Beyond risk mitigation of downstream processes, the finer lasers will provide improved surface finishes, including edge condition, and a smaller heat-affected zone [HAZ].”

Ultrafast lasers are becoming more prevalent and give users more tools to adjust beam parameters and optimize the penetration and integrity of welds. “A weld can be too shallow, too deep, too wide, or too narrow,” said Haag. “Every weld joint requires a unique set of parameters, such as power, pulse, pulse profile, and speed, which all play a role in adjusting and optimizing the process.” 

Such flexibility, when paired with optics and software that allow for real-time monitoring, enables the ability to adjust every weld for production tracking. 

Material challenges include nitinol, ultra-thin stainless and cobalt-chrome tubes, and high-temperature polymers. Laser cutting of nitinol, for example, often demands careful control of heat and post-processing to remove recast and heat-affected zones. “Contract manufacturers are investing in process development specific to these materials, including optimized laser wavelengths, pulse durations, and cooling strategies,” said Traverse.

More MDMs are asking for intensive tolerances and rigorous inspection requirements. For example, automated centerless grinding solutions can run “lights out” while maintaining tolerances of ±0.00002 in. However, “the ability to successfully measure a part is becoming as important as being able to make a part,” said Scott. “There are many companies out there that can make components for devices, but being able to pass gage R&Rs and test method validations has increased the cost of entry through proper equipment.”

Technological advancements for inspections continue to drive how products are designed, produced, and validated. “There is a clear trend toward in-line and near-line metrology that utilizes automated optical systems, vision inspection, and statistical process control tied into CNC controls,” said Traverse. “This enables real-time feedback and reduced inspection bottlenecks.” 

A growing number of MDMs rely on computed tomography (CT) for recommending specifications and testing parameters for new products by comparing the results back to the 3D model and understanding assembly influences in multi-component products. CT is also useful for detecting internal defects such as unwanted porosity in cast or sintered parts. 

Internet of Things 

Manufacturers that want to stay competitive must move at the speed of technology to provide a single-source ecosystem that brings programming, simulation, monitoring, measurement, and process control into one interface. This, of course, relies on the Internet of Things (IoT) to capture data, comprised of millions of data points, and turn it into a competitive asset. MDMs must be able to efficiently and accurately analyze this data to generate impactful and actionable insights. 

For example, “each new INDEX machine monitors spindle temperature, thermal variation, glass-scale feedback, and machine movement—every factor that affects precision,” said Huggett. “Before cutting a single chip, an operator can simulate the entire job with Virtual Machine and the WinFlex programming system. A simulated crash causes much less cost and disruption than an actual one.”

IoT connects machine tools with sensor data streaming (e.g., spindle load, vibration, temperature, and uptime) into centralized platforms for analysis. “Predictive maintenance and condition monitoring use IoT data and machine learning to detect anomalies and prevent unplanned downtime on CNC and laser systems,” said Traverse. “This enhances real-time overall equipment effectiveness [OEE] and process optimization, where shop-floor data is used to tune feeds/speeds, improve tool life, and stabilize processes for validated medical manufacturing.”

Automation, artificial intelligence (AI), and robotics are expanding the capabilities of machining and laser processing. For example, AI supports vision applications in both processing and inspections, as well as programming assistance. “The areas really coming into play for machining are advanced programming and more accurate simulations of tool paths with recommended tools,” said Scott. “If we can figure out ways to tie these all together—programming, optic path simulation, and vision—processing will be exponentially more efficient.”

Traditional automation, robots, and now cobots have had big impacts on the development of modern manufacturing. The next step is parts movers. “Beyond simple parts picking, or even the spider robots in a warehouse, will be droids that are integrated with manufacturing processes to move batches between operations at intervals,” said Andy Becker, vice president of pre-production for Cadence. “This will eliminate the need for fixed manufacturing cells to the same extent that CNC flexibility made pure mechanical setups obsolete. Low volume/high mix will benefit the most from this advancement.” 

Machining Versus Additive Manufacturing 

Although additive manufacturing (AM) enables extremely complex shapes, it has yet to overtake the functional precision of CNC machining, which maintains a distinct edge when it comes to critical surfaces, sealing interfaces, and tight tolerances. “When parts require geometric features unobtainable with subtractive machining, the most successful shops use AM to form the geometry, then use CNC to ensure performance,” said Huggett.

Most MDMs see CNC and AM as complementary technologies, rather than purely competitive:

• CNC machining provides superior precision, surface finish, and material versatility, and remains the primary choice for many load-bearing implants, instruments, and high-volume components
• AM is preferred for complex internal geometries, especially in porous structures and patient-specific shapes 
• Hybrid workflows combine AM’s design freedom with CNC’s accuracy and surface quality
• AM is the go-to method for rapid prototyping of tooling and fixturing, allowing quick turnaround and easy modifications at low cost during early development

“CNC machining still leads in tolerances, finishes, and scalability, while AM excels at complex geometries and rapid prototyping,” said Poff. “Together, they expand what is possible in medical manufacturing.”

In fact, as AM gets more advanced every year, “we will start to see more complex components coming from AM methods, instead of machining,” predicted Scott.

Moving Forward

A major concern within the industry is the critical lack of available talent and expertise. Advanced five-axis machining, micro machining, and laser process development require highly skilled engineers and operators, who are in short supply. Machines are also expensive—ultrafast lasers, high-end multi-axis CNCs, and automated inspection systems are costly, and ROI must be justified within tight medical pricing and volume structures. 

One of the top challenges to innovation in machining and laser processing is balancing ultra-tight tolerances with efficiency, handling high-performance materials, and integrating systems with automation. “On top of that,” said Poff, “standard compliance slows adoption of new technologies, while capital costs and the skills gap make it harder to scale innovations quickly.”

Advancements in programming, software, automation, workflow, and OEE will improve production efficiency, increase throughput, and reduce costs.

AI-powered CAM software will remove more human labor from programming machined components. “This is an add-on to traditional CAM software, driven by the massive knowledge of programs derived from human programmers. “It will provide a very high, consistent programming output for the first five years or so,” said Doyle. “As the market changes and practices shift, it is not clear how this software will keep up with changing demands. For most manufacturers, this will be a viable programming reduction for decades. The AI will need to monitor the variants of where human changes were made to its program to perfect the art of programming.”

The next generation of medical devices will be lighter, stronger, more personalized, and likely produced using a mix of machining, laser, coatings, automation, and AI-assisted engineering. 

“The machines themselves are increasingly capable of producing higher quality and precision components for the industry,” said Scott. “There is also a spike in equipment vendors, especially on the laser side. With all the custom machine needs and the ever-growing combination of sources, stages, and optics, there seems to be more integrators doing great things for the industry, and that has been fun to see.”

Vertical integration is another strategy that leads to faster throughput, reduced time to market, improved decision making, and better cost control.

“Many processes we once relied on suppliers for—specialized finishing, laser work, or secondary machining—now operate under our own roof,” said Couch. “This shift gives us greater control of quality, lead time, and total cost of production, which enables tighter alignment between engineering intent and delivered product. Vertical integration has also enhanced agility: when MDMs request changes or accelerated timelines, we can respond quickly instead of waiting on third-party queues.”

References
¹ tinyurl.com/mpo260141

Mark Crawford is a full-time freelance business and marketing/communications writer based in Corrales, N.M. His clients range from startups to global manufacturing leaders. He has written for MPO and ODT magazines for more than 15 years and is the author of five books.