Hilton Head 2014 Wrapup – 30 years of MEMS!

Guest post by Eric Levy-Myers

This was the 30th anniversary of the Hilton Head conference and the mood was one of amazement of how far the industry has come since the first meeting 30 years ago. The conference chairman noted that solid state sensors have taken over the world if only evidenced by the fact there are more smart phones than tooth brushes in the world. This set the stage for an underlying question of the conference: what happens to MEMS in the next 30 years? The Rump Session on Wednesday evening addressed the topic with special speakers.

The first day of the conference focused on Bio MEMS. In the first plenary session, Dr. Oliver Paul of the University of Freiburg spoke of directly linking to the brain to both sense and stimulate neurons. He noted with some humor that the brain has 10 to the 11th neurons. So given the number of neurons we can sense today, and a Moore’s law for probe sensors that doubles every 7 years, the curve says that we will be able to sense all the brains neurons by 2240.

The meat of his talk focused on four areas of invasive brain systems:

  1. Epicardial Grids that lay on the surface of the brain to control external machines such as robots for paraplegics to feed themselves.
  2. Array implants to sample many points in the brain.
  3. Deep Brain Probes to regulate diseases such as Parkinson’s.
  4. New Optical Stimulation technology that stimulate neurons based on wavelengths tuned to specific neuron types.

There are many challenges to getting these technologies into broad use, not least of which is the brain’s immune system attacks the probes rendering them useless in weeks or months. The research papers presented in the later sessions detailed how researchers are trying to overcome these and other challenges with Biomedical and Cellular Devices, and Bioassays.

Day two at the conference focused on the physical aspects of MEMS devices and fabrication. The plenary speaker Dr. Robert Carpick of the University of Pennsylvania introduced us to a term that most people had not heard of, “Tribology”.  As he explained; “We did not like the term ‘science and engineering of interacting surfaces in relative motion’ so we grabbed Greek words to make the word Tribology.” His thesis was that at the macro level, scientists and engineers understand how surfaces in contact interact.  They have methods to reduce the effects of this contact such as friction and material exchange. But at the MEMS level much less is known.  This is one reason MEMS devices avoid contact points and why MEMS manufacturers can be so frustrated by stiction or stickiness. Dr. Carpick explained several areas that hold promise to allow MEMS parts to touch and rub indefinitely without ill effect. One method was to have a sealed system fill with alcohol. The research papers in the technical session extended the topics to include Materials and Surfaces, Fabrication & Materials and Magnetic Transducers.

The Day three plenary speaker Dr. Kurt Petersen brought us his vast experience in successful entrepreneurship with MEMS companies and shared his lessons of what makes for successful startups. He set a very optimistic tone for the future of MEMS, one that is bright but not a given.   So he offered many juicy tidbits for anyone who wants to successfully start, run and exit a business. There were too many to repeat here, but these stood out:

  • Have a great team that is persistent and dedicated to the company’s vision.
  • Get your product into production fast. This fit well with the advice from the Sunday Workshop session where “fail fast so you can learn and adapt fast” was a theme.
  • Know your market inside and out because the investors will.
  • Inventing is great, but designing for manufacturing and efficient production is probably more important. You cannot make money if you cannot make and test it economically.

The afternoon research papers covered the latest research in High Q Resonators and Resonant Systems, promising, as did all the papers, much more MEMS innovation to come in the future.

The Rump Session highlighted the Sigma Group, a collection of SciFi writers that are distinguished by their previous careers as scientists, engineers and program managers. They also use these skills to advise the government about future issues of concern and opportunity. They spent the week talking to participants in the conference to gather data, so in the session they offered many insights.  After beers they shared even more interesting ideas and interactions with the audience!

Since the chair of the panel and the writers noted that SciFi correctly predicted most aspects of the internet and sensors we use today, we can perhaps assume today’s wild predictions are not as wild as we think. Perhaps the most interesting idea had to do with the brain systems discussed on day one.  Why not implant something that grows fiber into the nose that will enter the brain with millions of micro -strands that can act as probes. Overall, attendees and presenters at Hilton Head 2014 expressed much optimism that the MEMS industry will continue to grow into more unexpected parts of our lives as we move to a world of trillions of sensors and the internet of things.

The next conference is in Anchorage Alaska in June 2015. Hope to see you all there.

One-stop-fusion-shopping at freescale.com/sensorfusion

Guest post by Mike Stanley, Systems Engineer at Freescale

Back in February, I wrote an article describing the Xtrinsic sensor fusion library for Kinetis MCUs. Over the intervening months, we’ve made a number of improvements:

  • Demo and Development versions of the kit have been consolidated into a single installer that covers all options.
  • The limited “Evaluation” version has been removed. In its place, we offer free board-locked licenses tied to your Freedom development board. Licenses are generated automatically during the installation procedure.  You now have access to the full development version with your first download.
  • We’ve added support for two new base boards, bringing the total to four: FRDM-KL25ZFRDM-KL26ZFRDM-K20D50M and FRDM-K64F.
  • We’ve updated the Xtrinsic Sensor Fusion Toolbox for Android to support the new boards.  We also added several neat new features I’ll mention below.
  • We’ve published our Xtrinsic Sensor Fusion Toolbox for Windows.  It’s not a clone of the Android variant, although there are some common features.  It goes will beyond that tool, offering a deeper understanding into some of the underlying calibration and fusion routines.
  • We’ve reworked the Android app landing page into a one-stop-shop for all things related to sensor fusion.  Visit http://www.freescale.com/sensorfusion to find convenient links for everything you’ll need to get your project started.  That includes all of the above, plus training materials, and a link to the Freescale Software Services group.  They can provide quotes for production software licenses and custom consulting work.

Figure 1 will look familiar to readers who have experimented with the Xtrinsic Sensor Fusion Toolbox for Android. The rotating PCB display shown here was inspired by that app.  The Windows version gives you some really nice additions.  First and foremost are support (via UART/USB wired connections) for the FRDM-FXS-9AXIS and FRDM-FXS-MULTI sensor boards.  Unlike the FRDM-FXS-MULTI-B board, these do not have Bluetooth modules, and cannot be used with the Android version of the toolbox.  That’s no problem for the Windows variant, which uses the virtual serial port feature of the OpenSDA interface to talk with the boards.  Simply plug your boards into your Windows machine, start the application and click the “Auto Detect” button you see in the upper right of the figure.  The application will cycle through your PCs serial ports until it finds one connected to a Freedom board and running the template app from the Xtrinsic Sensor Fusion Library for Kinetis MCUs.  And if you have a Bluetooth enabled PC, pair it to your FRDM-FXS-MULTI-B and run wirelessly.  The communications interface is the same from the perspective of the Windows GUI.


Figure 1: Xtrinsic Sensor Fusion Toolbox for Windows – Device View

Just like the Android version, you can select from a variety of fusion algorithms.  Also shown are the version of embedded firmware running on your Freedom board, along with the type of board (assuming you have debug packets enabled on the board).



Figure 2: Xtrinsic Sensor Fusion Toolbox for Windows – Sensors View

Figure 2 shows you the “Sensors” view of the application.  Here you have current values and value versus time plots for raw accelerometer and gyro readings, plus calibrated magnetometer.


Figure 3: Xtrinsic Sensor Fusion Toolbox for Windows – Dynamics View

The “Dynamics” view, shown in Figure 4, lets you look at some of the virtual sensor outputs from the sensor fusion library.  These include orientation in roll/pitch/compass heading form, angular velocity and acceleration.  You might wonder what the difference is between “angular velocity” and the gyro readings on the “Sensors” page.  If your algorithm selection supports a physical gyro, then the values in Figure 3 have had gyro offsets subtracted from them.  If your algorithm does not include gyro support, then the angular velocity included here is the result of a “virtual gyro calculation” (see “Building a virtual gyro“).

The accelerometer reading on the “Sensors” page included the effects of both gravity and linear acceleration.  The “Acceleration” item on the “Dynamics” page has had the effects of gravity removed, so it represents only the linear acceleration of your board.



Figure 4: Xtrinsic Sensor Fusion Toolbox for Windows – Magnetics View

I think Figure 4 shows the neatest feature introduced in the toolbox.  Those of you who have seen prior generations of Freescale magnetometer demos will recognize computed hard and soft iron correction coefficients on the left, along with our “magnetic calibration meter”.  What’s new is the 3D-to-2D projection shown on the right.  These are the measured data points selected by the magnetic calibration library for use in determining the correction coefficients.  Ideally, the figure should be circular in shape, be centered at 0,0 and have a radius equal to the magnitude of the earth magnetic field.  Nearby magnets, fixed spatially relative to the sensor, will shift the center to some non-zero value.  Ferrous materials, fixed spatially relative to the sensor, will distort the circle into an ellipsoid, and possibly rotate it.   If sources of interference are not fixed relative to the sensor, you’ll still see distortion, but it will not behave in as predictable a fashion, and isn’t as easily corrected.   It’s educational to bring your board near sources of magnetic interference, and watch how the constellation will distort, then self-repair over time.


Figure 5: Xtrinsic Sensor Fusion Toolbox for Android – Device View

Figures 5 and 6 are screen dumps from the latest version of the Xtrinsic Sensor Fusion Toolbox for Android.  If you enable display of debug packet information in the preferences screen, you’ll get additional information displayed on the device view:

  • The version of software running on your development board (Version 417 in this case)
  • The number of ARM CPU “systicks” occurring during one iteration of the main sensor fusion loop.  Take this number, divide by the CPU clock rate, and you have the number of seconds required for each iteration through the loop.  For the case above, 514,860/48MHz = 10.7ms.  The number is computed in real time, and changes depending upon which algorithm you are running.
  • The board type you are using (a lot of the boards look alike)

I should mention that all of the above are also shown in the “Device” tab in the Windows-based toolbox.


Figure 6: Xtrinsic Sensor Fusion Toolbox for Windows – Canvas View


Figure 6 shows the new “Canvas View” which was just added to the Android version of the Toolbox.  It demonstrates how we could use the sensor fusion quaternion output to create a wireless pointer.  The accel/gyro and 9-axis algorithms work best.  The 3-axis options are pretty much worthless due to basic limitations of using just those sensors, although I will note that gyro-based air mice are possible, just not with this particular algorithm. Check/UnCheck the “Absolute” checkbox on the Fusion Settings Bar to switch between the “absolute” and “relative” versions of the wireless pointer algorithm.  And be sure to read the “Canvas” chapter of the in-app documentation to get full details about how it works.

Our goal with the new http://www.freescale.com/sensorfusion page is to give you everything you need to get started quickly.  Relevant hardware, libraries, tools, training materials and support options have been brought together in one place.  If you already have the CodeWarrior for Kinetis MCUs IDE installed on your Windows machine, and have your development boards on hand, you can be up and running ten minutes from the time you land on the page.  And as always, if you have suggestions or ideas for how to improve things, just drop me a line.

Report from Hilton Head 2014 Solid State Sensors, Actuators and Microsystems Conference


By Eric Levy-Meyers on behalf of MEMS Industry Group

Greetings from the Hilton Head 2014 Solid State Sensors, Actuators and Microsystems Conference. On June 8, I attended the optional Sunday Workshop: Frontiers of Characterization and Metrology for Micro- and Nano-Systems organized by Michael Gaitan of National Institute for Standards and Technology (NIST) and sponsored by MEMS Industry Group (MIG), who gathered a great group of speakers to address this topic.

NIST organized this session for the second time at Hilton Head. This program is designed to facilitate the process of improving the standardization of testing and standards that started at MIG’s Member-to-Member (M2M) Forum in 2010 and led to the NIST/MIG report “MEMS Testing Standards: A Path to Continued Innovation.” It was apparent from the interactions that the industry has realized that cooperation in the precompetitive space of testing and characterization must increase to allow the industry to grow and innovate.

At the Micro-Nano workshop at Hilton Head there were eight fascinating talks followed by a very lively panel discussion about the challenges and issues in MEMS characterization and testing. A few of the juicy conclusions are below. For all the details, be sure to subscribe to MEMSBlog so you can access later this week to get the whole report, which should be ready later this summer (free and available for anyone to download).

Key issues discussed include: 

  • Manufactures and users always find ways to use, and sometimes damage, MEMS devices in ways no designer or tester could predict. An example was a “blow out the birthday cake candles” Smart Phone application that had users blew into the microphone. Well, it took a while to link the app to damaged microphones (whoops).
  • Testers are not the bad guys – but they can deliver results people do not like to hear. But the faster people listen, the faster the devices can be fixed. In fact, “fail fast” can be a good approach to getting the best product out the door the fastest.
  • Since testing of MEMS devices leads to discovering novel failure modes, testing, failure analysis, manufacturing and design teams should be in close and continuous contact, especially in high volume systems.
  • The fact that customers always want devices that have more features and are faster, smaller and cheaper, leads to huge pressure on testing which never seems to have enough time to get ready for production.
  • New device types often require custom testing equipment and procedures, but over time, as these devices become more common, testing can be standardized.
  • It is easy to rely too much on tools instead of engineering intuition. There is no substitute for real world experience.

Calling all Innovators to Help Save Our Oceans


Guest Blog by Matt Huelsenbeck, Team Relations Manager, XPRIZE

A major problem facing the ocean is that air pollution is also ocean pollution. The surface ocean layer has become on average 30% more acidic since the Industrial Revolution due to the absorption of carbon dioxide from the atmosphere. These changes in ocean chemistry, dubbed ocean acidification, threaten many forms of marine life, fisheries, and other vital ocean services. But due to a lack of good tools to measure pH, there is little to no information on how ocean pH is changing on a regional level, or in places like the deep sea. We can’t tackle a problem we know so little about.

Therefore, the XPRIZE Foundation, the leading non-profit that’s solving the world’s Grand Challenges through large-scale incentivized prize competitions, is collaborating with ocean philanthropist Wendy Schmidt to offer $2 million dollars in prizes to address ocean acidification through the development of breakthrough pH sensor technology. The winning pH sensor(s) of the Wendy Schmidt Ocean Health XPRIZE will be radically more accurate, durable, and affordable. This is where you come in.

We are looking for teams of innovators to compete in this once-in-a lifetime competition to help tackle the issue of ocean acidification! Would you or someone you know, be interested in forming or joining a team? Skills as diverse as electrical engineering, materials science, data science, nanotechnology and chemistry could be part of the winning team. Registration is open, but closing soon, and we encourage you to fill out the Intent to Compete form today. By submitting your intent to compete form, you can build or join a team made up of innovators like yourself.

There are two prize purses available (teams may compete for, and win, both purses):

$1,000,000 Accuracy award – Performance focused (First Place: $750,000, Second Place: $250,000): To the teams that navigate the entire competition to produce the most accurate, stable and precise pH sensors under a variety of tests.

$1,000,000 Affordability award – Cost and Use focused (First Place: $750,000, Second Place: $250,000): To the teams that produce the least expensive, easy-to-use, accurate, stable, and precise pH sensors under a variety of tests. 
This is your chance to apply your skills to help improve our understanding of one of the oceans greatest threats, ocean acidification, and win up to $2 million dollars in the process! We hope to see you compete.