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Articles from 2021 In June

Got a Great Tech Story? MD&M Minneapolis Is Calling for Speakers

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Engineers, managers, and executives involved in the rapidly advancing medical device design industry interested in sharing their knowledge are invited to submit their proposal to speak at the Medical Design & Manufacturing (MD&M) Conference, to be held November 3-4, 2021, in Minneapolis, Minn.

The MD&M Minneapolis Conference provides medical device design professionals with valuable education, networking, and career guidance information. We are accepting speaking proposals for the MD&M Conference and Medtech Central theater, as well as the Engineering HQ theater, serving the ATX, Design & Manufacturing, MinnPack, and Plastec engineering communities. You may submit as many different proposals as you like. The deadline for proposals is July 16.

Learn more, find event details, and submit your proposal here:

We are accepting in-depth, detailed speaking proposals that may involve, but are not limited to, the following tracks and topics.


Regulations, Research & Development
Keeping current with medical regulations is an essential part of the research and design process. The challenge is to develop creative designs that meet regulatory requirements and at the same time take advantage of the newest material choices and innovative design methods. This track will look at ways to meet the latest medical device design challenges while also speeding the design process.

Topics include:

  • New and upcoming FDA regulations for medical devices
  • Next-gen materials and how to best use them
  • Using AI and machine learning to improve design
  • Innovative prototyping techniques
  • Integration of electronics/software into device design

Medical Device Design & Manufacturing
Medical design and manufacturing require an emphasis on quality from start to finish, while also implementing the latest best practices for design efficiency and production speed. This track will cover how to meet the tight medical quality assurance and quality control requirements, make use of the latest design and materials innovations, and manage risk to efficiently produce the most reliable devices.

Topics include:

  • Implementing tight quality assurance and quality contro
  • Sensors & AI in medical manufacturing
  • Materials choices and sourcing
  • Surgical robotics past, present, and future
  • Risk management best practices

Medtech Security, UI/UX, and Digital Transformations
Medical equipment must function extremely accurately, be usable in many situations by a wide variety of people and make use of the latest data management tools. Strict guidelines for patient information security must be met. This track will cover the interaction of medical equipment with safety, security, and data regulations.

Topics include:

  • Medical device security regulations
  • User training, safety, and patient experience
  • User interface and experience
  • How telemedicine & digitization are changing medical design
  • Digitization & data management

Innovation in Medical Design & Engineering
Challenge drives innovation, bringing about novel new ways of accelerating medical design and production for a wide variety of essential equipment. This track will focus on the latest advancements in medical design and engineering and how those can best be used in future development. Also explored will be what can be learned from the rapid development accomplished to battle the coronavirus and how can that information be used in future planning?

Topics include:

  • The role of automated or remote medical services moving forward
  • AI/machine learning application: diagnostics, therapeutics, automation
  • Working across industries and supply chains
  • Post pandemic: Working with regulatory bodies to reduce design burdens
  • Next-gen technologies: Miniaturization/wearables/implantables

If you have any questions, please email Conference Director Naomi Price ahead of the July 16 deadline at naomi.p[email protected]

Submit your proposal to speak

Learn more about MD&M Minneapolis

Do You Know the Latest Growth Markets for Test Equipment?

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Like other major industries, the test and measurement markets have been transformed by digitization. Advances in technologies, such as 5G, industrial IoT, cloud computing, and others, are the reason for this trend.  All these advances are making electronic devices more complex to design and test.

Further, digitization has resulted in several new types of tests. For example, more electronic devices need to be tested and measured in both internal combustion and electric vehicles in the automotive industry. Additionally, engineers will need to design new equipment, which must work in a harsh transportation environment.

T&M is Hot

The test and measurement equipment market is expected to grow from USD 27.7 billion in 2021 to USD 33.3 billion, according to a recent report from MarketsandMarkets.

Increasing demand is driving much of the market to grow significantly in equipment from the automotive, transportation, aerospace and defense, IT, electronics, semiconductor, industrial, medical, and others. The reports note that the healthcare sector is expected to exhibit the highest growth among these vertical markets during the forecast period due to the rapid development of new healthcare equipment, patient-monitoring systems, and personal emergency reporting systems.

However, the highest growth is expected in the test and measurement equipment market for repair and after-sales services. Repair services are provided for material and workmanship defects. Like troubleshooting, repairing includes detecting and eliminating faults present in a product in various stages of the product cycle. In addition, companies connect with their customers through toll-free numbers, online chat, or emails to provide round-the-clock technical assistance, cites the report.

5G – Automotive and IoT

The largest market for test and measurement equipment is currently North America. One of the drivers for this growth is the advancement of autonomous driving and Internet of Things (IoT) technologies. Both areas need faster (lower latency) and larger bandwidths, which can readily be achieved through 5G. As a result, the US is one of the active participants in the league for commercializing the 5G network throughout the country.

According to Rohde-Schwarz, the percentage of electronic devices in cars has been growing at an annual rate of 15%. New applications are continuously being added. For instance, mechanical components are being replaced by industrial robot components of steer-by-wire systems, radar-based safety systems, and new telematics systems designed for collision avoidance and traffic flow control applications. This advanced technology is driving demand for testing and measuring equipment to ensure the proper functioning of all systems and devices.

For example, before vehicle-to-everything (V2X) communication is ready for consumer use, developers must ensure the reliability and maturity of the technology. This means that rigorously testing and verification will be needed.

Field testing in the real world will have to be complemented with simulation testing in the lab. The latter is also critical for testing in the development and introduction phase to verify compliance with the standards. Traditional communication protocol testers will have to be used with scenario simulation tools.

Typical simulation tests would include emergency electronic brake light, left turn assist (LTA), intersection movement assist (IMA), and congestion control testing.

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5G communications require new types of test equipment.

John Blyler is a Design News senior editor, covering the electronics and advanced manufacturing spaces. With a BS in Engineering Physics and an MS in Electrical Engineering, he has years of hardware-software-network systems experience as an editor and engineer within the advanced manufacturing, IoT and semiconductor industries. John has co-authored books related to system engineering and electronics for IEEE, Wiley, and Elsevier.

Injection Moldable Material Exceeds 60,000 PSI Tensile Strength

In January of this year, Mitsubishi Chemical Advanced Materials (MCAM) expanded its KyronMAX product line beyond performance-grade polymers, such as PEEK and PEI, by adding engineering polymers, including polycarbonate, nylon, polyphthalamide (PPA), and even polypropylene. These new compounds unlock a wider range of applications in the automotive and mobility, recreational, electronics, and medical industries.

When it was introduced in 2014, the KryonMAX family of high-strength injection moldable thermoplastic compounds was designed to bridge the gap between traditional thermoplastics and carbon-fiber composites. “KyronMAX combines the best of both worlds by allowing engineers to injection mold high strength, carbon-fiber-reinforced thermoplastics in minutes with strengths that are comparable to metal,” said Dave Wilkinson, Technology Director for Mesa, AZ–based MCAM. “Combining specialized short carbon fiber and proprietary sizing technology produces molded parts that have significantly higher mechanical performance than was previously possible using long-fiber technology (LFT).”

Metal replacement has become a strategic element in most major OEM strategies for lightweighting and sustainability. KyronMAX technology has raised the bar for performance of injection moldable plastics and provides customers the opportunity to replace metal parts with plastic, said MCAM. KyronMAX parts that replace metal components on vehicles contribute to lower overall weight, which translates into a reduction of fuel consumption and CO2 emissions. Part cost can also be significantly reduced through the consolidation of several metal components into a single thermoplastic part by eliminating secondary operations during assembly.

MCAM continues to innovate in materials science, and it now offers materials with tensile strengths that exceed 60,000 psi (414 MPa), as shown in the video. In addition to improved processability, KyronMAX compounds exhibit mechanical properties that surpass conventional glass- and carbon-fiber-filled thermoplastic systems at similar fiber loadings. This allows for a reduction in filler loading, thereby increasing material strain and allowing the molded part to yield rather than fracture. These compounds are now being used to replace aluminum and steel in structural applications.

A quarter-turn latch found in the galley of a commercial aircraft illustrates how even a small weight reduction can have a large impact. Typically made from machined aluminum, this latch is molded using KyronMAX S-6230, a carbon-fiber-reinforced PEI compound. Switching to the thermoplastic provided a 45% weight reduction while still meeting mechanical and flammability requirements. MCAM’s exclusive Sprint technology — a platform for rapid injection molding of functional parts — was used to rapidly prototype components prior to full production.

Sprint technology uses additive manufacturing to produce a mold that is injected with the KryonMAX compound in the same manner as a metal tool. These rapid, cost-effective prototypes allow for rapid design iterations while testing under operating conditions.

KyronMAX can be compounded into any polymer. If an application requires the cost and property balance of nylon 6/6, for example, MCAM can formulate a nylon 6/6 KyronMAX compound that is stronger than anything currently available on the market. This technology ultimately offers customers the flexibility of selecting any polymer they want and combining it with KyronMAX fiber to create the strongest moldable compound in that category.

“KyronMAX compounds can significantly change the way engineers approach part design, manufacturing, and assembly,” said Wilkinson. “The combination of KyronMAX’s performance with MCAM’s proprietary high-pressure molding technology is now able to produce the highest strength structural components made from injection molded thermoplastics.”

Tyson Charts Course to Zero Net Greenhouse Gas Emissions

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American protein firm Tyson Foods recently announced plans to cut its greenhouse gas (GHG) emissions across its global operations by 2050 as part of the company’s broader efforts to counter the impacts of climate change.

“As the first US-based protein company in the food and beverage sector to have an emissions reduction target approved by the Science Based Targets Initiative, we hope to continue to push the industry as a leader and remain committed to making a positive impact on our planet, with our team members, consumers and customers, and in the communities we serve,” John R. Tyson, the firm’s chief sustainability officer, said in a release.

The new initiative expands Tyson’s earlier target of hitting a 30% reduction in GHG emissions by 2030. To reach in its goal, the company is updating its baseline for emissions to limit global temperature rise to 1.5°C by the end of 2023, based on the Paris Climate Agreement. It will also work toward using 50% renewable energy in its domestic operations by 2030, as well as support climate action policies through advocacy organizations like Net Zero Business Alliance.

During the effort, Tyson also aims to further its work to eliminate deforestation across its supply chain by 2030 and expand its 5 Million Acre Grazing Lands target for sustainable beef production by 2025. The company will also complete work to increase the land stewardship of acres used to grow crops for animal feed.

“We believe what good food can do for people and the planet is powerful. Our net zero ambition is another important step in our work toward realizing our aspiration to become the most transparent and sustainable food company in the world,” said Donnie King, the president and CEO of Tyson Foods, in a statement. “Partnership and collaboration will be critical to our efforts, and we look forward to working with our customers, supply chain partners, and other stakeholders to achieve net zero.”

The announcement of the company’s GHG emissions goals occurred as Tyson released its FY2020 Sustainability Progress Report.

Seeking Success as a Bitcoin Miner? Ditch Your Phone and Move to Texas

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Today's smartphones are a marvel of computing power. But even with amazing compute capabilities, smartphones are a poor choice to use if you want to mine for bitcoin.

While smartphones do technically have enough power to mine for cryptocurrency, other miners have much more powerful computing platforms, making it useless to use a smartphone.

To mine for cryptocurrencies like bitcoin, one needs to validate blockchain transactions by solving complicated math problems. Unfortunately, such a compute-intensive task requires GPUs or computer processors that consume a massive amount of energy.

Is it possible to pull together the resources of several smartphones together to form a mining pool or mobile mining farm? In theory, the answer is yes. However, such a pool would still have an insignificant amount of computing power than miners who used dedicated PCs and servers with custom ASIC chips.

But there is another problem. Both Google and Apple have banned the use of on-device mining on Android and iOS hardware. For example, Google's latest Developer Program Policy (effective January 20, 2021) states: "We don't allow apps that mine cryptocurrency on devices. We permit apps that remotely manage the mining of cryptocurrency."

Applications that manage cryptocurrency mining control platforms remotely, either in the cloud or to a local computer. For example, programs like MinerGate Control enable users to keep track of remote mining operations. The mining is not performed on a smartphone.

Texas Migration

To successfully mine for cryptocurrencies, you must have the right equipment and plenty of available energy. For these reasons, China has long been home to more than half the world's bitcoin miners. But not anymore, as Chinese leaders in Beijing have recently begun to enforce a severe crackdown on bitcoin mining and trading. Why?

The official reason is that China is failing to meet its environmental climate change targets. Therefore, leaders have decided that power-intensive cryptocurrency miners are the main culprits behind its missed targets. But others suggest that China, like other countries, is worried about the illegal use of cryptocurrencies for money laundering.

Where will these miners go? It seems that a great many might migrate to Texas, which has an abundance of solar and wind power combined with an unregulated market. But the latter point is seen by many as a negative, as the unregulated market structure exacerbated recent bad weather in Texas that completely shut down its energy grid for many cities. Indeed, blackouts are still a common occurrence in some of the areas hardest hit.

Regardless, Texas's political leaders welcome cryptocurrency miners and the bitcoin business. Also, Texas has some of the world's lowest energy prices – for now. But those prices may not remain as favorable if big storms continue to shut down the energy grid in the coming years.

John Blyler is a Design News senior editor, covering the electronics and advanced manufacturing spaces. With a BS in Engineering Physics and an MS in Electrical Engineering, he has years of hardware-software-network systems experience as an editor and engineer within the advanced manufacturing, IoT and semiconductor industries. John has co-authored books related to system engineering and electronics for IEEE, Wiley, and Elsevier.

Good Reads: Are You Ready for the Top 10 Design News Articles in June?

Our June reads were as lively and vibrant as summer, including impressive semiconductor displays and stunningly beautiful cars. Humor was also shining from unique roller coaster rides to 20 ways to make engineers laugh. And don’t miss our selection of noteworthy technical women.

John Blyler is a Design News senior editor, covering the electronics and advanced manufacturing spaces. With a BS in Engineering Physics and an MS in Electrical Engineering, he has years of hardware-software-network systems experience as an editor and engineer within the advanced manufacturing, IoT and semiconductor industries. John has co-authored books related to system engineering and electronics for IEEE, Wiley, and Elsevier

Want to Impact Asset Modernization? Here Are 5 Critical Simulation Needs

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Across the federal, aerospace, and defense (FA&D) ecosystem, accelerated modernization through digital transformation and simulation remains a critical priority to ensure warfighters stay ahead of the threat.

Over 90% of aerospace and defense executives intend to reinvent their digital business. Yet fewer than 10% have made impactful progress. Closing this gap represents a significant competitive advantage for warfighters and aligns with the U.S. DoD Digital Engineering Strategy. The faster it’s closed, the greater the benefit.

Model-based approaches are maturing across the acquisition process thanks to integrated simulations that scale from physics-based simulations of components to entire missions. Such simulations will play a critical role in accelerating digital transformation by delivering state-of-the-art technology to the warfighter faster, with fewer resources and a higher probability of success. This type of digital mission engineering (DME) has been calculated to deliver an overall program acceleration of 6x.

Whatever the program, from the development of trusted and assured microelectronics to hypersonics, realizing these benefits requires five capabilities.

1. Deployable Across the Acquisition Process

Intuitive interfaces, workflows, and computational power now make it easy for almost any engineer — novice or expert — to significantly expand analysis of alternatives studies with near real-time results, dramatically expanding the ideation process.

In manufacturing, research highlights a 25% greater improvement in overall equipment effectiveness (OEE).

Similar technology is now being used to optimize operations and sustainment through physics-based digital twins, driving operational availability while reducing maintenance costs.

2. Integration from the Microchip to the Mission

Today, a hierarchy of simulation tools is used from component design to mission assessment. Unfortunately, in many cases, the tools used at each level — components, systems, systems of systems, and missions — lack integrated digital connectivity.

With digital mission engineering, a pervasive simulation environment that integrates all scales of models is possible. The DME helps establish a continuous high-fidelity digital thread from the microchip to the mission that predicts operational outcomes much more effectively and identifies critical issues earlier. The result is that required capabilities are delivered to the warfighter faster and much more affordable.

Integrated across all operational domains, DME enables engineers to simulate assets and predict how they perform in a mission’s operational environment.

For example, DME continues to impact numerous high-profile government programs, including NASA’s OSIRIS-Rex mission, where an uncrewed spacecraft recently collected samples of minerals from a potentially hazardous asteroid projected to re-enter the solar system the end of the next century. Understanding the minerals’ chemical and physical characteristics will prove vital for managing the threat. Leveraging DME, engineers determined the spacecraft’s nominal trajectory and complex maneuvering sequence that allowed it to safely land on the asteroid’s surface.

3. Accuracy and Validation

With lives and mission success at stake, physical testing has been the go-to method for validating mission-critical and safety-critical performance. However, FA&D leaders realize simulation has evolved to validate complex military systems’ real-world capabilities rapidly and cost-effectively in a virtual world — thus complementing physical testing while significantly streamlining development processes.

For example, simulation is being used to streamline the development of avionics for U.S. military aircraft. 

4. Open and Collaborative Environment

Modern military system acquisition involves an ecosystem of heterogeneous multitool simulation capabilities, often spread across suppliers, geographies, and functions. This requires open interfaces that are interoperable with multiple enterprise capabilities for product lifecycle management and resource planning. The days of a restrictive singular-provider simulation environment that is unique or tied to a specific program are over.

Fortunately, a new era of open and interoperable simulation platforms has arrived, providing simulation and process data management, performing integrated and customizable enterprise workflow chaining and optimization, and ushering in a gateway to high-performance computing capabilities.

The U.S. Army has increased access to and scalability of complex government simulation code due to a customizable simulation environment.

Organizations must embrace these new capabilities and ecosystem opportunities to amplify the impact of a simulation further.

5. Workforce Enablement

Enterprises are struggling to recruit engineers with the skill sets to drive digital transformation while simultaneously addressing knowledge loss due to a retiring workforce.

By teaming with approved commercial providers and their simulation centers of expertise, leveraging expert-led, application-relevant, and enterprise-scalable training with highly reliable technical support and services, engineers can be onboarded faster. Additionally, both new and existing engineers upskill much more quickly — accelerating the adoption of cutting-edge simulation capabilities.

Federal aerospace and defense leaders can benchmark their own DME maturity against these five critical capabilities and determine what they can do in each area to accelerate — ensuring the warfighter stays even further ahead in an ever-evolving threat environment.

Retired U.S. Air Force Brig. Gen. Steve Bleymaier is the vice president for global strategy and government programs, federal aerospace, and defense at Ansys. Previously, he spent more than 28 years with the U.S. Air Force leading strategic initiatives in aircraft sustainment, supply chain, and logistics. (Image Source: Ansys, DME)

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Digital Mission Engineering (DME) is the critical capability.

How to Keep a Flipped Switch From Bouncing Like a Golf Ball Dropped From the Roof

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If a newcomer to the electronics engineering community were to ask me to pick a topic that would follow them around throughout their career -- popping up when they least expect it like a surreal version of Whac-A-Mole -- the subject I would select would be that of switch bounce.

Switch bounce is a relatively easy concept to wrap your brain around, but it can be a trickly little scamp to address with a high degree of confidence. Actually, that’s not strictly true because many an engineer has been extremely confident in their switch bounce solution, right up until the time when an unanticipated bounce triggered an unwanted event.

Switches Bounce

The underlying idea is that the moving contacts in switches bounce. That’s what they do. This is true of toggle switches, pushbutton switches, micro switches, limit switches... in fact, just about every switch other than devices like mercury tilt switches, with which most engineers never come into contact (no pun intended) anyway.

To the uninitiated, a switch is either Off or On. When someone activates or deactivates a light switch on a wall, for example, the associated light appears to react immediately. In reality, for some period of time, the switch will be bouncing (turning on and off) like a ping pong ball dropped onto a hardwood floor. However, this bouncing -- and the corresponding flickering of the light -- occurs too quickly to be perceived by our biological sensory systems. (There’s also the thermal inertia of the filament in an incandescent bulb coupled with the persistence of vision, but let’s not wander off into the weeds.)

By comparison, in the case of a microcontroller unit (MCU) with a clock running at millions of times a second, the bouncing associated with every activation and deactivation may be perceived as tens or hundreds of events.

Consider the normally open (NO) terminal associated with a single-pole, single-throw (SPST) toggle switch, for example (Figure 1) (SPSTs with normally closed (NC) terminals are also available). Observe that bouncing can occur on both the active and inactive “edges.” Also, that the bouncing may extend all the way between logic 0 and logic 1 levels (which I think of as “clean bounces”) and/or between a good logic level and some intermediate voltage level (which I think of as “dirty bounces”).

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Switch bounce on an SPST-NO toggle switch.

Similarly, in the case of a single-pole, double-throw (SPDT) switch, bouncing may occur on both the active and inactive edges of both the NO and NC terminals (Figure 2).

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Switch bounce on an SPDT BBM toggle switch,

Observe that only clean bounces are shown in this image for the sake of simplicity. Also, we are assuming that this is the most common form of SPDT -- a break-before-make (BBM) -- which means the moving contact breaks the existing connection with the current throw before making a new connection with the new throw (although they are less commonly used, make-before-break (MBB) implementations are also available).

So, how long might switch bounce persist? The problem here is that a lot of “established wisdom” is conveyed by word-of-mouth. When I was starting out as a newly minted bright-eyed bushy-tailed engineer, for example, a senior engineer told me that bouncing would certainly have ceased within 1 millisecond (ms), so I’d be fully covered if I assumed a worst-case scenario of 2 ms. I took him at his word. I have no idea why I never thought to actually verify this for myself using simple test rigs (like the circuits shown above) and an oscilloscope.

By comparison, embedded systems guru Jack Ganssle is cut from a different piece of cloth because he took a bunch of different switches, subjected them to exhaustive analysis (it exhausted me just reading about it), and wrote his Guide to Debouncing. Jack determined that the switches bounced for an average of 1.6 ms with a maximum value of 6.2 ms. Wow! That was way more than I was expecting.

As one final point of data, one of my friends, who used to be a technician in the US Air Force, told me that they assumed a worst-case bouncing scenario of 20 ms and -- since this is a nice round number -- I’m happy to go with the flow. Hey, if it’s good enough for the US Air Force, it’s certainly good enough for me.

So, how should we set about debouncing the signals coming out of our switches? In fact, we have two main options because we can opt for hardware or software solutions. To be honest, there are almost as many hardware techniques as there are hardware designers, and there are almost as many software solutions as there are software developers, so we will touch on only a few here.

Traditional Hardware Debounce Techniques

Let’s start with some traditional hardware-based approaches. In the case of an SPST switch, a very common option is to use an RC delay coupled with a Schmitt inverter (Figure 3).

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Debouncing an SPST switch with an RC delay coupled with a Schmitt inverter.

Note that the diode is optional, but its presence simplifies the timing calculations, which can be especially useful if we wish to trigger actions both when the switch is activated and when it’s deactivated. With the diode in place, the capacitor charges via R1 and discharges via R2. If we omit the diode, then the capacitor still discharges via R2, but it charges via (R1 + R2).

By comparison, in the case of an SPDT switch, the crème de la crème solution is to use an SR latch formed from two back-to-back NAND gates (two back-to-back NOR gates can also be employed) (Figure 4).

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Debouncing an SPDT switch with an SR latch formed from two back-to-back NAND gates.

To be honest, we could talk about these traditional hardware solutions for hours, but there’s not much point because relatively few designers employ these techniques these days. Also, there is a more modern hardware solution, but first...

Software Debounce Techniques

Today’s embedded systems developers tend to debounce signals from their switches using software techniques. The big problem here is that the majority of software developers have little idea as to how switch bounce works in the real world, so oftentimes they employ snippets of code provided by their peers, where this code may or may not be as robust as one might hope.

There are all sorts of software techniques available. A common approach is to use a counter. Also, to loop around checking the state of things (like the switches) and performing any associated actions once each millisecond, for example. Let’s suppose we are waiting for the output of the switch to transition from a 0 to a 1. Let’s also suppose we have decided to wait for 20 ms following the final bounce before we do anything.

We start with our counter containing zero. After we detect our first 1, every time we cycle round our loop, we check to see if the signal is still 1. If so, we increment our counter; if not, we reset our counter to zero. It’s only when the counter contains 20 that we know the signal has been a steady logic 1 for the past 20 ms, at which point we can perform any desired actions, after which we start waiting for the output of the switch to transition from a 1 to a 0.

Now, remember that I’m a hardware designer by trade, so you rely on any software advice I give at your peril. Bearing this in mind, I favor another software approach that I find easier to wrap my brain around. The idea here is to have a 20-bit shift register, which we can implement using an unsigned 32-bit integer variable.

Every time we go round our main loop, which we are assuming is once every millisecond in this example, we shift the contents of our shift register one bit to the left, read the state of the switch, and load its 0 or 1 value into the least-significant bit (LSB) of the register. When all 20 LSBs are 0, then we know that the signal from the switch has been 0 for at least 20 ms. Similarly, when all 20 LSBs are 1, then we know that the signal from the switch has been 1 for at least 20 ms. Deciding how we subsequently employ this information is easy-peasy lemon squeezy. For example, we could create a simple state machine with six states: CurrentlyZero, TransitioningToOne, JustBecameOne, CurrentlyOne, TransitioningToZero, and JustBecameZero.

I’m Lazy!

I’m afraid to admit that, as the years go by, I’m starting to become a little lazy. I no longer wish to spend my valuable time on this planet slogging away on mundane tasks like debouncing the signals from switches when there are so many other fun things to do.

Also, while debouncing a single switch is no problem, things become more painful as the number of switches mounts. In the case of my Prognostication Engine (don’t ask), for example, there are eight toggle switches, ten push-button switches, and two knife switches.

Thus, the switch debouncing in all of my recent hobby projects has been achieved using dedicated ICs from LogiSwitch (in the spirit of full disclosure, I should point out that I’m a member of their Technical Advisory Board). These little beauties are available in 3-, 6-, and 9-channel versions. Also, they are available in dual-in-line (DIL) lead through-hole (LTH) packages suitable for prototyping on breadboards, and as surface-mount devices (SMDs) for those who prefer them. For example, consider a 3-channel LS18 device (Figure 5) (the “SW0” vs. “SW1” nomenclature is unfortunate, but that’s the way the cookie crumbles and the switch bounces, I’m afraid).

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The 3-channel LogicSwitch LS18 addresses both noise and switch bounce.

The first thing to note is that we don’t need to use a pull-up resistor on the switch because this function is included in the chip itself.  Also of interest is that any noise spikes are rejected, which gives me a warm fuzzy feeling of happiness. The debounced output follows the input 20 ms after the final bounce, which is negligible when it comes to human-machine-interface (HMI) applications.

If you do demand “instant” response (within a couple of nanoseconds) for an automation application, for example, then LogiSwitch provides another family of chips that do just that. This other family also provides a unique 1-wire handshake interface on each channel that can be used to “clear” the switch event, but those chips will form a story for another day.

How About You?

So, how about you? Have you run into any problems related to switch bounce that you would care to share with the rest of us? Also, what debouncing solution(s) do you tend to favor?

Bio-Metal Is Stronger and Lighter Than Titanium With 50 Percent Renewable Resin

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A Skydio drone is used to demonstrate an Arris Composites bio-metal composite camera mount.

Arris Composites’ Additive Molding Technology has already demonstrated its ability to meld the strength of carbon fiber with the manufacturing speed of injection molding, but now the company is targeting metal applications with a new product it calls Bio-Metal.

The “bio” portion of the material comes from Arris’s use of 50 percent renewable and recyclable resign in the products it makes with this new material. The result is a non-metallic carbon fiber composite, but Arris dubs it Bio-Metal because it is stronger and lighter than titanium.

A development challenge has been increasing the amount of renewable material that can be blended into the resin for Bio-Metal because the renewable resin has different characteristics from the traditional petroleum-based resin. “What we have seen is that this steady progress upward has gotten to a place where it can be a meaningful portion,” explained Arris Composites CEO Ethan Escowitz. “The challenge with most biomaterials, any time you time to drive it too high, you take a performance hit that customers won’t use." The material is a bio-based composite for metal replacement.

Escowitz described an unpleasant personal experience with dog clean-up bags made of plastic that is biodegradable. Unfortunately, he found the bags start breaking down while he was still using them!

With a 50 percent blend, Arris has found satisfactory performance for its Bio-Metal, which is now in use for consumer goods like the Skydio drone’s camera mount bracket, an application where lightness and strength are at a premium. These uses will accelerate the production of Bio-Metal while Arris continues to develop for additional markets, he said.

“Medical is a really interesting space,” Escowitz stated. Is replacing material like titanium for human implants an ideal use for this technology? “This material is peak carbon fiber. It is implantable grade,” he said.

No only is it good enough for use in patients, but carbon fiber’s characteristics make it better for implants than titanium. “It has a bunch of advantages. When you X-ray where you have surgeries they want to be able to see very well to make sure there are no infections. With composites, you can see the joint in x-rays.”

Not only that, but titanium implants can be too stiff in some ways, and Arris’s Bio-Metal can be a superior substitute for bone. “It better mimics the modulus of bone,” said Escowitz. “It's a more compliant material that behaves more like bone.”

Medical implants aren’t an area where we want to skimp to save money, but at the same time, medical costs are extravagant, so if Bio-Metal can make implants less expensive, that’s beneficial. “The feedstock material is incredibly expensive for medical-grade material,” Escowitz noted. “They’re machining that away today to make the parts.”

While Arris is actively pursuing medical device opportunities, the company recognizes that medicine is not its area of expertise. “The main thing is that we are looking for partners that would commercialize the space,” Escowitz said.

Meanwhile, the company is looking to move from consumer products like drones and into other volume markets, such as auto parts, where Bio-Metal can be used for products like bumpers and crash structure, where its high strength and light weight are helpful.

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Arris bio-metal is suitable for parts like automotive crash structures.

Want Improved Medical Treatment? How About Custom-Designed Patient Therapies

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Researchers have developed a multi-material approach to 3D printing custom artificial body parts and other medical devices for better shape and durability well as bacterial resistance.

A team from the University of Nottingham led by Yinfeng He, transitional assistant professor in the faculty of engineering, developed a computer algorithm that can design and manufacture 3D-printed objects comprised of two polymer materials of differing stiffness that also prevent the build-up of bacterial biofilm.

The aim of the technology is to combine multi-material 3D-printing techniques for optimized performance for custom medical prosthetics and other devices, He, who also is a researcher at the university’s Center for Additive Manufacturing, told Design News.

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A bacteria-repelling artificial finger joint with customized strength distribution made with a new multi-material 3D-print process developed by researchers at the University of Nottingham’s Center for Additive Manufacturing.

“Through this technique, we are able to pick the materials based on the specific needs of a patient, combine them, and shape them into a device so it can perfectly fit the patient,” he explained to us. “To achieve this, we are continuously exploring new chemistry and adjusting our 3D printers to ensure the materials will ‘collaborate’ in one device and serve the patient better as a ‘team.’”

Meeting the Challenge

Because every person is different, it’s nearly impossible for mass-produced medical devices to suit the specific and complex needs of every patient, He said. To solve this problem, his team set out to create a single, intelligent design process that can be applied to 3D-print medical devices with customizable shapes and functions.

The innovation the team developed has two key aspects. One is in materials, He told us. The team created two new ink formulations—each of which demonstrates different mechanical performances but both of which are resistant to bacterial biofilm formation--that are compatible with inkjet-based 3D printing, he explained.

“The success of these two inks enabled us to apply the latest inkjet-based multi-material 3D printing technology to design and produce medical devices with not only customizable geometries but also customizable functions,” he told Design News.

The second aspect the team created was to apply a generative algorithm to design the distribution of each material to maximize its unique performance and guide the 3D printing process, he said.

“The main finding of our research is that when we are combining different materials into one device, we found a computer-aided method to design a ‘blueprint’ for each material so they can be assigned to the position where they are most needed,” he told us. “The overall performance of such a device is better than randomly arranged ones.”

Promising Results and Future Goals

Using their technology, the team successfully produced a bespoke finger-joint implant device that can combat bacterial resistance and infection as well as 3D-printed pills that can deliver medicines based on the need of the patient, researchers said.

However, these objects are the tip of the iceberg for what they believe they can fabricate using their technology, he told us.

“We believe this multi-material 3D printing technology combined with computer-aided design could bring a revolution in the production of customized devices with customizable functions,” he told Design News.

Researchers published a paper on their work in the journal Advanced Science.

The team’s next steps will be to work with collaborators to demonstrate that these complex and personalized devices can be used on actual medical patients, He said. Researchers also will explore the use of this new design and manufacturing toolset in other medical devices with more customizable functions, he added.

Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 20 years. She has lived and worked as a professional journalist in Phoenix, San Francisco, and New York City. In her free time, she enjoys surfing, traveling, music, yoga, and cooking. She currently resides in a village on the southwest coast of Portugal.