Stephen Las Marias: Tell us more about yourself, Despina, and your lab-on-a-chip project.

Dr. Despina Moschou: I always start by introducing people to what lab-on-a-chip is in general. Lab-on-a-chip is not my invention—I have to be very clear on that. Professor George Whitesides from Harvard and Professor Andreas Manz first suggested it. They came up with this idea in the mid-1990s. The concept was miniaturizing a complete biomedical laboratory in a microchip. This vision is what we, the scientific community all over the world, have been trying to do for the past 20–30 years.

Before I became involved in this field, my original background was purely electronics. I’m an electronics engineer, I graduated from Athens, and I have a Ph.D. in microelectronics. During my first post-doctoral research, I ran into the field of lab-on-a-chip—in particular, microfluidic devices. Since then, I have been involved in that because the impact of this technology is enormous once it reaches everyday life.

What does this technology do? Imagine if you could have the whole biochemical laboratory on your hand. Wouldn’t that be cool? And apart from being cool, let’s assume we have a biomedical laboratory such as a health-care facility. What do you do when you want to identify a diagnosis? Either you or your doctor will take a sample—such as blood, urine, or any other kind of biological sample—and will take a bottle of it and ship it to a laboratory. The laboratory will do an analysis. It will take a few hours, days, or even weeks, and then you will receive the results. This is the current routine in health-care practice for all kinds of diseases, whether infectious, routine checking, or monitoring your pregnancy or cancer treatment. Wouldn’t it be great if we could avoid all the delays? How different would it be if instead of taking things to the laboratory, we could bring the laboratory to the people who need it.

And because you don’t have to delay, treatment can start immediately. You wouldn’t have to wait. Starting treatment is extremely important for overcoming any kind of disease. It will also have a huge impact in environments and countries where you don’t have access to health-care facilities whatsoever, such as remote islands or low- and middle-income countries where you don’t have access to health-care facilities with laboratories. In all of these cases, having a miniaturized laboratory can make a huge difference. This is roughly the vision of what we are trying to realize with our Research at the University of Bath.

Barry Matties: The technology itself is really interesting because they’re using these miniature micro-pumps to move fluid around, and the idea was to actually incorporate it into the build of the circuit board. And it’s really a game-changer. What’s interesting about this also is it’s one and done, meaning you use it, you throw it away and you buy more. So, from a consumption point of view, millions and millions of units will be sold. And you’ve already had success in creating the lab onboard and doing diagnostics, correct?

Moschou: Yes, we have.

Matties: This really goes with the continued desire for smaller, faster electronics, more affordable, and it’s going to revolutionize the way that medical diagnostics is done.

Moschou: Exactly. What I have been driving for the past few years is trying to implement Lab-on-Chip technology on PCBs. At the moment, and ever since the invention of lab-on-a-chip, every research laboratory in the world has been using their own in-house technique to fabricate those devices. We don’t have lab-on-a-chip technology with one way to manufacture things. In electronics, we have PCBs. We have the standard card that we all use to simulate and design boards, and manufacturers globally that have standardized procedures because this is an industry that’s been around for many years.

In lab-on-a-chip, this is not the case. We are still at the research stage and are gradually transitioning into actual commercialization of devices the past few years. One of the problems delaying this process is that we don’t have factories. We don’t have a lab-on-a-chip factory where I can make something in my lab, design it, and then I can go and get millions of them. This is why I have been trying and persisting on the lab-on-PCB approach because we can actually use the factories that are out there right now fabricating electronic boards and transition into something more advanced—something smaller and more intelligent that can add further functionality to the electronic boards. This time, we can incorporate miniaturized channels to transport the liquids and the fluids that we want to analyze, which are called microfluidic tunnels. We can have analytical biomedical devices on a PCB.

This is not conceptual. I have been presenting for the past few years on the projects and prototypes we have made. We started making things in the lab with PCB technology, but lately, I’ve been working with several manufacturers around the world. I have shown several prototypes for many applications—mainly medical applications—involving DNA and protein detection for different cancer diagnoses. Currently, we are working in the lab on several of the prototypes for diagnosis. It’s a proven concept. It can be done.

Las Marias: Thank you, Despina. Meanwhile, Tom and Kaspars, please tell us more about Vexos and your roles in the company.

Tom Reilly: Sure. My name is Tom Reilly, and I’m the director of marketing and sales operations for Vexos.

Vexos is a full service, high-mix, low- to mid-volume mid-tier electronics manufacturing services (EMS) provider, operating in focus market sectors such as: medical, industrial, semiconductor, automotive, safety, security and industrial internet of things (IIoT) markets. Vexos has a global manufacturing presence with two manufacturing sites in China, Shenzhen and Dongguan along with its North American sites in Markham, Ontario, and LaGrange, Ohio. All sites are ISO-9001 and ISO 13485 certified. We have more than 25 years’ experience in providing a high-level of electronic manufacturing services, value engineering solutions and global supply chain management services that supports all our sites. We are deeply involved with provisioning highly complex, fine-pitch electronics assemblies, electromechanical assemblies, full turnkey solutions and custom mechanical parts.

The medical and life sciences sector is about 10–15% of our business and we currently specialize in manufacturing a number of difference products such as; visual aid, monitoring systems, diagnostics and connectivity-type products. As we grow in this market sector, we continue to meet the needs of our customers through a range of offerings in manufacturing and engineering services. Apart from our electronic services, which include printed circuit board assembly (PCBA), sub-system assemblies, and full box-build product. Our engineering services include design for supply chain (DFSC), design for fabrication (DFF), design for manufacturability (DFM), design for test (DFT), and complementary development services.

It’s important to mention we work very closely with our customers and partners and some of the companies are world-renowned corporations, who rely on these high-level services. We also worked with smaller, localized companies to help develop and bring their products to market.

As I mentioned, we work very closely with customers and provide them with value engineering support in the early stages of product development, from quick-turn prototyping to new product introduction, right through to full mass production, whether that be localized within one of our North American facilities or one of our China facilities for a more low-cost, high-volume region. These facilities also give our customers the opportunity to launch products into the market as well.

Kaspars Fricbergs: I am the VP of quality for Vexos. I’m based in the Toronto facility, and I’m responsible for the coordination of the quality functions across the various Vexos locations. I’ve been with the organization and its predecessors for about 17 years now. I have a long background in quality in electronics and electromechanical devices, including experience in the medical realm as well. We’re ISO-13485 registered at all our manufacturing facilities, as well as ISO 9001 certified. In China, we are IATF 16949 registered in one of our facilities; and both of our facilities have ISO-14001 and OSHAS 18001 registrations as well.

Las Marias: Earlier on, Despina was telling us about her problems and challenges when it comes to the lab on a PCB. From your perspective as an EMS provider covering the medical electronics industry, what are some of the top challenges you’re seeing in this sector?

Fricbergs: There are a number of challenges associated with the field. I was about to say one of the top ones is the regulatory regime in medical devices. We are an EMS company, so we’re not design responsible, and we don’t do product submissions to the FDA; but there are a whole host of regulations surrounding the manufacture of the products that need to be met. Those are largely covered by the ISO 13485 registration, but there are also the regulatory regimes of the FDA and other local, jurisdictional regulations. In Canada, we would need to deal with Health Canada requirements as well for any products that would be marketed and sold in Canada.

The ISO 13485 certification largely covers the specific requirements that the FDA has outlined in their Quality System Regulation, 21 CFR Part 820, although there are some differences. You also have FDA regulations surrounding the use of software and the compliance of software, that’s 21 CFR Part 11. You have specific requirements for documentation, validation, traceability, validation of process, validation of software, medical device files, and medical device histories. All of that has to be in place to provide the level of assurance to regulatory authorities and to our customers that we produced the product properly according to the processes that have been defined. Some of those requirements go beyond and are different than those of other industries.

Another challenge that we often run into is simply the time to market. Often, customers can come with an immature design. It may not be manufacturable, so Vexos can help in those cases. We offer design for assembly feedback services and design for test feedback services, that can help make the products manufacturable and bring the product to market faster. Sometimes with new product launches, because our customers don’t have a strong view of the manufacturing process, they come with an idea, they may have a design that’s been provided that may not be manufacturable. Or they may not have explored all the regulatory regimes and may not be clear on what requirements they may specifically have for quality.

We’ll work with them on that, but again, a typical challenge is simply the time to market. Usually, when a design and concept have been firmed up and there’s some backing for it, the desire is to quickly get it out to market, or at least get it into the approvals stage from a regulatory point of view.

Those are some of the bigger challenges we have. Of course, we have to have a very strong eye on the product’s quality and make sure we’re complying with all the requirements and regulations in order to avoid any situation that’s going to affect our customers.

To read the full article, which appeared in the November 2018 issue of SMT007 Magazine, click here or Download and read the full PDF version

For more information on Medical Electronic Manufacturing Services – Contact VEXOS today!  or Call 855-711-3227

Vexos, is a mid-size global Electronics Manufacturing Services (EMS) and Custom Material Solutions (CMS) company, providing complete end-to-end supply chain management solutions in electronic and mechanical products for Original Equipment Manufacturers (OEMs) and new emerging technology companies.  

Vexos services extend over the entire electronic product life cycle, from value engineering services for product development to prototyping and New Product Introduction (NPI) through to the growth, maturity and end-of-life phases with a strong focus and commitment to quality and customer service satisfaction.

With facilities in United States, Canada and China Vexos can efficiently compete in today’s marketplace, primarily focus within automotive, industrial, networking, communication, medical and security market segments.  Vexos enables their customers to focus on their core business, reduce your cost, speed your time-to-market and gain a competitive advantage.

The post A Look at Medical Electronics Design and Assembly Challenges appeared first on VEXOS.

I mentioned “de-slugging” above.  What that means is the removal of vent channels and spacer holes that keep two conductive screen-printed silver pads and traces apart, so they don’t make contact and create an electrical short.  This was the method used in 1978 and is still the primary way of isolating electric circuits.  The de-slugging process was tough and takes a lot of time.  Many companies have either developed equipment to help expedite this process, or they have moved the labor-intensive assemblies to low country cost centers.  Membrane switch production is very labor intensive.  To put this in perspective, there are set-ups for every layer of a membrane switch.  If a graphic overlay has 5 colors, there are 5 set-ups for the printing processes.  If there are two circuit layers, then there are set-ups to print and die cut those layers, as well as the spacers.  You can see how this adds up very quickly.  To combat those costs and maximize the membrane switch value, VEXOS turned to China in the late 1990’s for production of their membrane switches.

Membrane switches have come a long way since 1978.  They were first introduced in 1973, but it took many years before the technology totally caught on.  The global Membrane Switch market is expected to reach USD 13.14 billion by 2025, according to a new report by Grand View Research, Inc.  In the beginning membrane switches were simple, non-tactile circuits separated by a thin spacer layer.  These switches would achieve 1-2million cycles before breaking down.  Eventually the market asked for tactile feedback on switches and this was answered by adding stamped metal domes or thermo-forming poly-tactile domes.  Initially these technologies were fraught with issues.  The metal domes would be placed on top of the circuits and sometimes the circuit would close before the dome clicked, or the dome would click, and the circuit would not actuate.  This caused frustration and damage by the customer.  Poly-domes weren’t much better.  The early poly-domes were mushy and had a very short life cycle of 250,000 cycles before they would break down. 

The interface of choice for a multitude of applications

With the large number of user interface options available today, it is easy to forget why the membrane switch is an excellent choice for instrumentation. The basic advantages are still the same as they were two decades ago, when membrane switches became the interface of choice for a multitude of applications, such as consumer products, medical devices, high-end appliances, industrial controllers, and automotive controls. These applications have been enhanced by developments in materials, processes, and design expertise.

Membrane switch applications are well suited for a multitude of electronics, which are limited to a specific or small number of functions, are portable, and require a high degree of visibility. Membrane switches are particularly suitable for handheld applications and portable devices because they are lightweight, low profile, durable, easy to clean, and RoHS-compliant.

Six key features

We focus on the six key features of membrane switches that contribute to the optimal design of any user interface electronic product.

1. Graphics

The biggest advantage of a graphic overlay on any device instrument is its ability to be seen in a 180° radius. Warning lights or other functional indicator lights can be viewed from a distance at various angles. As the top layer of the membrane switch, the graphic overlay is the direct interface between the product and the end user. Besides the obvious function of defining the switch locations and functions, it can also serve purposes of product enhancement and differentiation. With an essentially unlimited color palette, the graphic overlay can provide aesthetically pleasing yet highly functional characteristics to the product. Very simple color and artwork adjustments provide low-cost model or functional differentiations even though the lower switch layers remain constant, which can help to keep total program costs down. 

Hard coated overlay materials have excellent resistance to adverse environments. Selective applications of texture coatings provide durable and pleasing background and interface areas, while allowing lower layer displays to be highly visible and undistorted. In addition, lower layer displays, and LEDs can be hidden using appropriate dead fronts and transparent colors. Embossing may be used to give the panel a three-dimensional look and feel.

2. Shielding

Membrane switches can easily provide protection against electrostatic discharge (ESD). An inner layer of the switch assembly can take such discharges to ground. Innovative uses of double-sided polymer circuitry (D/SPC®) can provide the path to ground as part of the switch circuitry, thus eliminating the need for extra shield tails or tabs. The use of D/SPC can also help to reduce the footprint of the switch circuit, eliminating potential problems with discharges to the edges of the membrane panel. This shield layer can simultaneously provide EMI/RFI protection. Printed shield layers can be tailored to each unique application to provide optimum shielding effects and prevent unwanted interference from incoming or outgoing signals. Shielding can generally be accomplished without compromising the performance or aesthetics of the switch.

3. Seal-ability

One of the biggest threats to any type of user interface is the risk of water or chemical ingress into the switch cavity. A membrane switch can be sealed against various types of environments typically used in a portable handheld environment. This can be achieved with a full perimeter seal or gasket within which the circuit tail exit is routed. With the proper design and material choices, not only can the switch array be sealed against the environment, but it can also seal the enclosure to which it is mounted. The sealed membrane switch can also provide highly visible status indication through the use of low profile surface mounted LEDs.

4. Illumination

There are two common and proven methods of illuminating a membrane switch: LEDs and electroluminescent panels. The LED is a very effective way of communicating — either close or at a distance — a device status, even at oblique angles and differing light conditions. Advances in polymer surface mounted technologies, as well as commercially available low-profile LED packages, offer a reliable and effective way to incorporate status indicators into a membrane switch. The combination of chip bonder and conductive epoxies provide the strength and conductivity necessary to attach .010″-tall LEDs to flexible polymer circuits. LEDs are best suited for status indicators but can be adapted to provide backlighting. This becomes a design challenge as the overall height of the switch is increased when using LED backlighting.

Electroluminescent (EL) lamps are not interchangeable with LEDs for lighting purposes. The EL lamp is most appropriate for backlighting in low light situations. It is not suitable as an indicator light or in daytime or bright light conditions. The advantage for backlighting is an even light source (no point source of light is evident) and can be provided in a very thin layer. Typical EL thickness is approximately 0.010″.

5. Tactile Feedback

Tactile feedback enhances error-free data entry and can be achieved with two different materials. Metal dome constructions are used for high reliability applications where a high number of actuations and extreme temperature cycling is anticipated. Metal domes are offered in a variety of sizes, shapes, and actuation forces. A second option is a formed polyester dome. Actuation force is highly customizable with this approach because there are numerous combinations of dome heights, sizes, and shapes. With either material, the user confirms switch closure by “feeling” the switch dome collapse, which acts as a shorting patch to close the switch loop.

6. RoHS Compliance

As RoHS compliance is a requirement for most electronic devices built today across multiple industries. Typically, there are no banned substances in the basic building blocks of membrane switches if screen printed conductive inks are used. Pressure-sensitive adhesives, the polyester film used for the substrate, and the inks used for graphics are generally free of restricted substances as well. 

Choosing Vexos as your Membrane Switch partner

The membrane switch industry has come a long way since those early days.  At VEXOS, we now have flat non-tactile switches that will exceed 10,000,000 actuations.  Our metal domes come in an array of actuation forces and are formed to be placed directly on the circuit ensuring a consistent make/break of the switch and dome.  VEXOS and our supply partners have developed a unique poly-tactile graphic layer that provides outstanding tactile response, reduced material usage and a life expectancy of 2 million cycles.  We have also developed proprietary epoxies to place LED’s and 7 segment displays directly on the membrane circuits.  Our switches can be terminated with open tails coated in carbon or with male or female clincher connectors. 

I can assure you that in 1978 I never dreamed that my career would revolve around the membrane switch and touch screen industries.  With that said, I am thrilled to have been a part of the technologies evolution and the growth of the industry. 

VEXOS’ engineers are capable in helping take a concept to a finished product and are ready to help.  By designing the switch and tooling in house, manufacturing all hard tools, steel rule dies and embossing tools in house we can provide the most reliable parts at a competitive cost with industry leading delivery times.  Touch the Future with VEXOS.

For more information on Membrane Switches Contact VEXOS today! 

or Call 855-711-3227

Vexos, is a mid-size global Electronics Manufacturing Services (EMS) and Custom Material Solutions (CMS) company, providing complete end-to-end supply chain management solutions in electronic and mechanical products for Original Equipment Manufacturers (OEMs) and new emerging technology companies.  

Vexos services extend over the entire electronic product life cycle, from value engineering services for product development to prototyping and New Product Introduction (NPI) through to the growth, maturity and end-of-life phases with a strong focus and commitment to quality and customer service satisfaction.

With manufacturing facilities in LaGrange Ohio United States, Markham Ontario Canada and 2 locations China. Vexos can efficiently compete in today’s marketplace, primarily focus within automotive, industrial, networking, communication, medical and security market segments.  Vexos enables their customers to focus on their core business, reduce your cost, speed your time-to-market and gain a competitive advantage.

The post The Evolution of Membrane Switches in Today’s Electronic Markets. appeared first on VEXOS.