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Components are getting smaller and smaller, especially in the medical, automotive, and electronics markets. New micromachining technology, including advanced laser markers with superior beam quality offers similar results to traditional machining technologies, but they’re less expensive, faster, and more flexible. The fiber marker technology can be one-half to one-third the cost of standard technology.
High-volume manufacturers looking to meet miniaturization challenges while reducing costs can use the single-mode fiber marker to achieve excellent results on a range of materials, including steel, nickel, titanium, silicon, aluminum, and copper. The method should be considered by those thinking about updating or replacing electric discharge machining (EDM) equipment, as well as those who might otherwise turn to 532nm and 355nm lasers.
Micromachining refers to making small features using standard machining operations such as drilling, cutting, scribing, and slotting on a smaller scale. There is no official scale for determining that an operation is micromachining, but a good benchmark is when the features cannot be seen without one’s glasses, or you are seeing results without seeing details. In other words, you might have no idea what was done to the material to get a particular effect. For example, if you drilled 50µm holes in a piece of copper you would see light, but would not be able to see how big or small the holes were that are letting light through.
In the hands of a skilled operator, recent advancements in the use of a fiber-laser marker for micromachining can create desired features not normally associated with this equipment. The major benefit of this approach is that fiber-laser markers are much less expensive than standard equipment used for micromachining.
Working successfully at such a small scale requires the right tool as well as knowledge of how to use it to achieve the desired results, in terms of both quality and speed of material removal.
For example, Miyachi Unitek recently introduced the LMF2000-SM single-mode fiber laser marker, which offers parameters and controls to enable micromachining of fine detail dimensionally and at excellent removal rates.
The laser marker features high beam quality, with an M-squared of less than 1.3, which produces a focused optical spot size down to 20µm, making it particularly suited for scribing and cutting a wide variety of materials, including alumina, silicon, copper, and aluminum foils. In addition, the use of selectable pulse-width waveforms with different peak power characteristics enables tuning of the removal rate and feature surface quality. This independent control of pulse width and peak power with pulse frequency offers control and process tunability advantages compared to traditional q-switched lasers.
The scan head that moves the laser is also a key part of the system, providing sufficient high-speed movements with suitable repeatability and accuracy.
Fiber laser micromachining technology can be used for a wide variety of applications, such as selective plating removal for solder barrier, solar cell scribing and hole drilling, hole drilling of stainless steels for medical hypo tubes and fluid flow control systems, and cutting of sub-0.02" thick metals for fast part prototyping.
Single-mode fiber laser markers can be used as an alternative to more costly micromachining technologies, including sinker EDM equipment, or 532nm and 355nm Nd:YVO4 lasers.
For example, Figure 1 shows how the technology could be used as a replacement for sinker EDM machines. The picture on the left shows the drilling of a 150µm hole, ±10µm in 200µm thick steel, with no post processing. The minimal amount of debris and tight hole tolerance was achieved in 50% of the time taken by sinker EDM equipment.
In addition, because the laser marker offers a working X-Y area, multiple parts can be completed in a single loading operation, as opposed to one-up loading on sinker machines (unless an additional investment is made in motion equipment). This advantage makes the fiber laser marker return on investment even more compelling.
The fiber laser can also process difficult materials such as thin-sheet material and foils. Also in Figure 1 is a spiral with 100µm wide elements machined in 50µm thick copper foil.
Figure 2 shows a comparison of drilling silicon using a fiber laser marker (left) and a 355nm UV laser source (right). The UV laser provides better quality than the fiber laser, but the fiber laser results are good enough for this particular application. In addition, the fiber laser was 17 times faster than the UV laser and 50% of the cost. Note that the UV hole shows a roundness defect, due to a laser path program error.
Figure 3 compares the quality of holes drilled with a 20W single fiber laser (left) and 5W 355nm laser (right) in 0.008" stainless steel in the same processing time.
The finesse and machining control that is possible using the single-mode fiber laser, in which the fiber laser marker was used to machine a 25µm thick metal foil to a 13µm depth. The application was to provide a preferential failure point in a component. The channel width was 75µm and the depth variation over the entire area was ±1µm – equal to taking material that is one-fourth the width of a human hair and leaving only about one-tenth of it after micromachining.
Ceramic is another commonly used material in microelectronics, and a 355nm laser is typically used for scribing and drilling of ceramic materials. The fiber laser marker can avoid micro-cracking for a wide variety of features in ceramic materials.
There are many applications that can benefit from the laser’s capability to selectively remove platings or coatings on metals, ceramics, and even plastics. Fiber laser machining techniques have shown good results in micromachining solder barriers or solder dams, thin film resistor/capacitor trimming, and active layer removal in battery foils for welding purposes. This selective and tailored layer removal process is usually impossible during the component or part production process, because masking the area is simply not feasible.
The laser can select the exact resistance value for a circuit. It also can be used for resistance or capacitance trimming, as part of a dynamic iterative removal and measure tuning process in which removal areas may change from component to component.
The single-mode fiber laser marker can be a cost-effective micromachining workstation for drilling, cutting, scribing, and ablation for a variety of applications. This desktop mini machining center provides the benefits of dual- or multi-purposing to maximize ROI.
It must be noted that, in addition to having the right tool for the job, it is important to know how to use the tool efficiently and effectively. Miyachi Unitek has developed a number of machining methods that enable the single-mode fiber laser to perform beyond its surface characteristics, while ensuring that the stability of the process is in line with volume production.
About the author: Dr. Geoff Shannon is the laser technology manager at Miyachi Unitek and can be reached at email@example.com or 626.930.8448.
In March of this year, the FDA put out a shocking statistic: from 2003 to 2012 medical device recalls almost doubled from 604 to 1,190. More disturbing, there was a decided rise in incidents where the defective device carried a reasonable probability of death and couldn’t be recalled due to the fact that thousands of devices had already been implanted, ranging from defibrillators to replacement joints. A recall for a medical device in the Western world will also carry the added liability of not just being recalled in the country of origin but create a worldwide reporting obligation.
Whether the recalls were as severe as defective implantables or minor quality issues on diagnostic devices, the message is the same: impeccable design, due diligence, and manufacturing quality should be the primary focuses of medical device manufacturers.
Coupling this, the demand for innovation is high in a global economy where keeping ahead of your competition is essential and preventing market-share loss is a constant struggle.
So how can medical device manufacturers ensure that their products exceed industry standards and prevent recall disasters while still being profitable?
The answer lies in advanced design and manufacturing software that combats these issues at the front end of the design process by highlighting potential quality issues in the concept phase – challenging the product design team to find simplified design solutions that incorporate new technologies and materials.
Product lifecycle management (PLM) technologies have taken great leaps in the last decade, but not enough to identify and circumvent many quality and production issues later on the manufacturing floor. You need to have a concise methodology that forces the design team to break traditional design paradigms and objectively analyze a design from a risk-mitigation standpoint. Few software systems encapsulate this sort of rigorous methodology into their code.
When searching for suitable software, there is a list of must-have elements. The first element is that the software should incorporate lean design methodology. With all of the time and money spent on good manufacturing practices, many companies don’t realize that you cannot truly achieve lean manufacturing without employing lean design. Another FDA study found that 44% of voluntary quality recalls during the period of the study were directly attributable to poor design. Previous to that study, Munro & Associates identified that 70% of cost and quality issues take shape in the design phase. However, this is a solvable issue that can be eliminated in this phase if the right design practices are followed.
Manufacturers need to take a holistic approach to product development. They need to attack inefficiencies and bottlenecks on many levels simultaneously, while identifying and eliminating future potential manufacturing, quality, and supply chain issues early in the concept design phase. A combination of vetted market knowledge, design, manufacturing, and cost expertise is needed to bring this goal to fruition.
In order to achieve a lean design no matter what software you use, a cross-functional team needs to be assembled. Teamwork is essential in the product development cycle, and the cornerstone of innovation is a diverse team. To produce a successful and streamlined product launch, the team should be formed from product design engineers, quality, finance, supply chain, and manufacturing experts.
Customer value insights should come from market research, while the executive stakeholder – the champion of this particular project or department – should provide oversight.
The next element is the ability to thoroughly and accurately map the design in a visual step-by-step process that captures all of the proposed parts and all of the required manufacturing and assembly steps. The process should include a concise set of coded symbols that contain a range of data sets the team chooses.
All new product developments contain a series of knowns and unknowns. The baseline mapping process begins with inputting the known data from past product launches. Next, it moves forward into comparing and analyzing proposed new or redesigned parts that are continuously challenged using the lean-design methodology.
Each symbol on the map should capture every detail of the part, including weight, a should-cost piece cost, tooling costs, known quality and warranty data related to existing or similar parts, labor costs, machine cost centers, and time values provided from the team. The rollup of this data should not only give the team a more accurate sense of total accounted costs, weights, and timing, but also highlight areas of concern and places for improvement. This is an ongoing process that works in tandem with and throughout CAD modeling.
The design map is a living document, a guide to be used on the way to completing the final product. Key performance indicators (KPIs) should also be continually referenced and included in this process.
Once all data is entered, a scoring system needs to be implemented in order to address problem parts or assemblies. The team will now have a better visual sense of areas for improvements and potential failures. It is only after this point that the team can honestly asses the manufacturability of design concepts.
All parts should then be challenged to either combine them with other parts or to altogether eliminate them, reducing unnecessary complexity, cost, and quality issues. Added complexity brings added chances for errors and failures. This is especially true in product design. All efforts must be exerted to simplify the design to create more reliable products while reducing labor time, piece costs, and potential liabilities for the manufacturing floor. You don’t have to apply lean manufacturing methods to a cell that never existed if that assembly was eliminated in the design phase.
Another key element is comparing materials and selecting new technology and manufacturing processes. You should do this while considering how the form and function of each piece plays into the whole system as dictated by the customer’s objectives. To provide better quality and reduced costs, several software programs exist that can make material selection easier and quicker. Some of these can now be accessed completely from the cloud or on a smart phone.
Proactive quality predictor tools – such as the cost of quality or the quality report card – are a much needed element in product design software. These tools can calculate sigma and alert the engineer to quality issues and costs in the design phase – before they are experienced in manufacturing and endured for the lifecycle of the design. Using historical data from similar parts or platforms, the engineer can quickly track sigma and mitigate quality risks early, preventing costly recalls and warranty risk exposure.
The next step is to address potential ergonomic issues and dangers. Very often product design engineers are unaware of ergonomic consequences that can be experienced on the manufacturing floor due to the architecture of their designs. So, it is critical to include the manufacturing team early on to illuminate such issues. Using the design map, parts and processes that fall into the ergo category should be marked and highlighted in order to remove them before they are discovered downstream.
At this juncture, poka-yoke issues should also be addressed. Poka-yoke is a Japanese phrase that means to “error-proof” or “fail-safe.” From a design perspective you want to design parts so that they cannot be assembled wrong (backwards, upside down, etc.) Including potential Poka Yokes in the design stage is less costly and more effective than trying to eliminate errors with manufacturing techniques. This is an often overlooked pitfall that is truly low hanging fruit. Having manufacturing involved at the concept stage helps prevent these lurking future quality costs.
Energy consumption and carbon footprint should also be tracked, quantified, and reduced by applying these methods within the software. As carbon taxes become more topical, and energy consumption and reduction is becoming a focus in the global manufacturing arena, all efforts should be employed to address these issues early on.
An added benefit of using software that addresses all of these factors is that you will speed your product’s time to market. A consistent focus on reducing product development times ensures that vital intellectual property leaps are not impeded and potential market advantage is not lost to your competitors.
Investing in cutting-edge product design software tools ensures a faster product design cycle with reduced risk and increased profit while improving a company’s design culture. That can take your company from good to great.
Munro & Associates
About the author: Alistair Munro is director of business development at Munro & Associates/Lean Design Canada and can be reached at Alistair@leandesign.com.
We all would like to think that the place where we feel most vulnerable – a health care facility – is as safe as it could be. No wonder the recent reports claiming it is possible – even easy – to remotely manipulate a piece of medication dispensing equipment, access bloodwork results, or alter digital medical records attracted so much attention.
Clearly, the issue has the U.S. Food and Drug Administration’s (FDA) attention, as evidenced by its draft guideline on cybersecurity for medical devices and the warning to address the cybersecurity risks, both issued in June 2013. With the rise of wireless, Internet, and networking technologies in medical devices, the need for effective cybersecurity measures to assure device functionality and to secure patient information has become more important than ever.
The FDA guideline calls on medical device manufacturers to consider security during device design and to consider cybersecurity risks as part of the required risk analysis. Additionally, a matrix linking the risks to the control measures is recommended. Although the FDA guidelines themselves are not legally binding, they do represent the FDA’s view, or interpretation, of the regulations. Therefore, manufacturers can expect the FDA to request evidence that the guideline is followed when submitting the 510(k) documentation for clearance or a Premarket Approval Application (PMA).
The guideline lists the following vulnerabilities that can impact medical devices and hospital network operations:
The FDA guidance on cybersecurity states that manufacturers should consider three principles and develop a set of security controls to assure medical device cybersecurity: confidentiality, integrity, and availability.
To demonstrate to the FDA that cybersecurity has been properly addressed, section five of the guideline calls on medical device manufacturers to specifically provide the following documentation:
In addition to the FDA requirements, many hospitals require manufacturers to provide evidence that their devices are secure and not susceptible to cybersecurity risks. The best way for manufacturers to demonstrate that their devices are hardened against attacks is to integrate cybersecurity solutions during the early stages of product development and document the assessment and remediation actions.
Manufacturers can also implement a a three-prong cybersecurity lifecycle approach to evaluate susceptibilities:
As the industry, public, and regulatory agencies become more aware of the issue, a variety of services are being developed and introduced to the market. The services help manufacturers analyze current threats and vulnerabilities within medical device software and communication systems and range from design consulting, assessment and testing, and finally, remediation. These services can help companies not only meet regulatory and health care provider purchase requirements but can also protect the brand name and reputation by reducing the possibility of a successful attack.
Cybersecurity experts should work alongside the design team to identify the potential cybersecurity risks based on the device features and help them design a more secure product. They advise on methods to address the risks, document them, and suggest controls to manage the risks. Devices should undergo a number of assessments or tests to identify their vulnerabilities:
Even though we may still feel vulnerable at a hospital for a while, the good news is that significant measures are being taken to reduce the harm from potential cybersecurity attacks. Manufacturers can help ensure digital defenses of medical products by incorporating cybersecurity expertise in the design phase, resulting in safer products in the Internet of Things world. Health care providers, in turn, can include medical device cybersecurity in their governance, risk, and compliance strategy.
About the authors: David Surber is VP Medical Products and Carol Sams is VP Partner Development at TÜV Rheinland. Surber can be reached at 925.249.9123 or firstname.lastname@example.org, and Sams can be reached at 415.389.0298 or email@example.com.
Twisting a screwdriver, removing a bottle cap, and peeling a banana – a few simple tasks that are tricky to pull off single-handedly. Now a new wrist-mounted robot can provide a helping hand – or rather, fingers.
Researchers at Massachusetts Institute of Technology (MIT) have developed a robot that enhances the grasping motion of the human hand. The device, worn around one’s wrist, works essentially like two extra fingers adjacent to the pinky and thumb. A novel control algorithm enables it to move in sync with the wearer’s fingers to grasp objects of various shapes and sizes.
“This is a completely intuitive and natural way to move your robotic fingers,” says Harry Asada, the Ford Professor of Engineering in MIT’s Department of Mechanical Engineering. “You do not need to command the robot, but simply move your fingers naturally. Then, the robotic fingers react and assist your fingers.”
The robot, which the researchers have dubbed Supernumerary Robotic Fingers, consists of actuators linked together to exert forces as strong as those of human fingers during a grasping motion.
To develop an algorithm to coordinate the robotic fingers with a human hand, the researchers first looked to the physiology of hand gestures, learning that a hand’s five fingers are highly coordinated. While a hand may reach out and grab an orange in a different way than, say, a mug, just two general patterns of motion are used to grasp objects: bringing the fingers together, and twisting them inwards. A grasp of any object can be explained through a combination of these two patterns.
The researchers hypothesized that a similar biomechanical synergy may exist not only among the five human fingers, but also among seven. To test the hypothesis, graduate student Faye Wu wore a glove outfitted with multiple position-recording sensors attached to her wrist via a light brace. She then scavenged the lab for common objects. Wu grasped each object with her hand, then manually positioned the robotic fingers to support the object. She recorded both hand and robotic joint angles multiple times with various objects, then analyzed the data, and found that every grasp could be explained by a combination of two or three general patterns among all seven fingers.
The researchers used this information to develop a control algorithm to correlate the postures of the two robotic fingers with those of the five human fingers. Asada explains that the algorithm essentially teaches the robot to assume a certain posture that the human expects the robot to take.
For now, the robot mimics the grasping of a hand, closing in and spreading apart in response to a human’s fingers. But Wu would like to take the robot one step further, controlling not just position, but also force.
“Right now we’re looking at posture, but it’s not the whole story,” Wu says. “There are other things that make a good, stable grasp. With an object that looks small but is heavy or slippery, the posture would be the same, but the force would be different, so how would it adapt to that? That’s the next thing we’ll look at.”
Wu also notes that certain gestures – such as grabbing an apple – may differ slightly from person to person, and ultimately, a robotic aid may have to account for personal grasping preferences. To that end, she envisions developing a library of human and robotic gesture correlations. As a user works with the robot, it could learn to adapt to match his or her preferences, discarding others from the library.
Massachusetts Institute of Technology
Watch the MIT-developed device that enhances the grasping motion of the human hand with two robotic fingers at http://bit.ly/1q20ALw.