MEMS And Sensor Tech For The Next Decade

Most of today’s blockbuster MEMS products – from pressure sensors and resonators to accelerometers and microphones – originated from academic research, a trend that Alissa M. Fitzgerald, Founder & Managing Member, A.M. Fitzgerald & Associates, expects to continue. While many of these potentially game-changing new technologies will require many more years of intensive development and up to $100 million in investment to reach full commercialization, Fitzgerald sees their potential for generating new waves of activity and opportunity in the MEMS and sensors industry.

SEMI’s Maria Vetrano caught up with Fitzgerald to preview her presentation, Emerging MEMS & Sensors Technologies to Watch as We Enter a New Decade, at the upcoming MEMS & Sensors Executive Congress.

SEMI: What are your top three emerging MEMS and sensors technologies with the greatest promise?

Fitzgerald: Let’s start by defining emerging. In researching this topic for MSEC, I reviewed a year’s worth of academic papers to search for compelling technologies that will emerge five to 10 years from now. While these applications are not yet commercially ready, they bear a distinct presence in academic literature, and some have even reached the proof-of-concept phase. They all have the potential to advance user functionality derived from MEMS and sensors in very meaningful ways.

Next-generation micromirrors
I’ve noticed renewed interest in micromirrors, driven by interest in LiDAR for autonomous vehicles, in fiberoptic networking, and in VR/AR glasses and headsets as well.

Newer generations of micromirrors will use piezoelectric films to enhance optical performance. Piezoelectric actuation can pivot the mirror to a much larger angle than older-generation electrostatically actuated micromirrors. This is important for wider-angle scanning for LiDAR – as well as for other applications – as it enables the creation of a larger picture image.

Piezoelectric films can also be used to change the shape of the mirror surface to enable a variable-focus mirror. This is useful on two fronts: It supports depth-of-field adjustments and it alleviates the need for extreme precision in packaging of optical devices, improving both cost and yield.

Event-driven sensors/zero-power/ultra-low power sensors
Sensors that draw no power, or that draw just small amounts, by activating only upon a triggering stimulus, are enormously exciting. Their extremely low power consumption addresses one of the most significant obstacles to creating large-area sensor networks: the problem of too-frequent battery changes.

In addition, while most sensor nodes today broadcast a large stream of data back to the mother ship by radio, these event-driven or zero-power sensors consume only a small amount of power because they activate the radio only to transmit essential data.

Resolving the power-consumption problem with sensors will allow deployment of large-area sensor networks in remote or inaccessible locations, highly useful for applications such as monitoring infrastructure.

Bacterial sensors
Sensors that can detect the presence of bacteria, as well as the type, have widespread applicability beyond medical uses. They would be particularly useful in food-safety applications as they can identify particular strains of bacteria, such as E. coli, before the beef leaves the processing plant or the spinach ships from the warehouse. This could offer dramatic improvements in food safety over the Centers for Disease Control (CDC) and U.S. Food and Drug Administration’s (FDA’s) food safety program, which only flags foodborne illness when a cluster of people are seriously ill.

Researchers are also designing bacterial sensors for rapid point-of-care (POC) diagnostics to detect, for example, sepsis early, potentially saving lives.

SEMI: You’ve said that some future MEMS and sensors will use alternatives to silicon. When might we see MEMS and sensors printed on paper or other flexible materials – and for which applications are they suited?

Fitzgerald: We’re seeing an enormous amount of development of sensors made on paper, plastics and even textiles, materials that are readily available, inexpensive and flexible.

What’s gating our progress right now is manufacturing infrastructure. At present, researchers are using inkjet printers, 3D printers, etc. to manufacture prototype sensors, but in most cases, they would need to move to roll-to-roll printing to scale up. I think that we’re looking at a decade before we see these sensor technologies reach the mass market.

When they do arrive, we’ll see sensors that we can easily affix to any kind of carton, wrapper or packaging used with food or other disposable items. Traceability and status of perishable items in particular will allow consumers to track food from the farm or factory to the warehouse, store and, finally, to the home.

Implementing these kinds of sensors would also help the environment. According to the Natural Resources Defense Council, in the United States alone up to 40 percent of our food is wasted annually, in part because we fear it’s gone bad. If consumers feel assured that their food is safe, they will waste less. And wasting less means that we can grow less food to feed the same number of people. We’ll also reduce the volume of food waste that goes to landfills.

SEMI: What can the MEMS industry do to promote the use of more environmentally friendly materials in its products?

Fitzgerald: Some of this is already underway. More companies in our industry are adopting Restriction of Hazardous Substances (RoHS) standards to get rid of heavy metals, such as lead, cadmium or other hazardous materials, in their electronics.

We could also produce disposable sensors on paper or on biodegradable plastics, which would decompose within a few months, and we could use safer metals, such as gold, magnesium or zinc, to reduce hazardous metals’ contamination in landfills. While it’s not feasible to make all sensors biodegradable, the market for such sensors could be massive.

As companies (and individuals), we should also work hard to design electronics that consume less power, because this ultimately translates to fewer disposable batteries in landfills.

SEMI: What would you like MSEC attendees to take away from your presentation?

Fitzgerald: I’d like to make two main points. First, the trend to use other non-silicon materials to make MEMS and sensors is real and inevitable. It’s a matter of when. Anyone building a gas or chemical sensor on silicon should look at how to do it on paper or plastic because there are great future applications incorporating flexible, disposable sensors in packaging of all types. That’s the low-hanging fruit.

Second, to support this technology development trend, we must look seriously at manufacturing infrastructure because we will need completely different sets of equipment, environments and consumable materials to manufacture MEMS and sensors on paper or plastic. Sensor manufacturers could prepare for this future expansion by beginning to collaborate today with companies that already produce paper and plastic goods.

Alissa Fitzgerald, Ph.D., founded A.M. Fitzgerald & Associates, LLC (AMFitzgerald), a MEMS and sensors solutions company, in 2003. She has over 20 years of engineering experience in MEMS design, fabrication and product development. Prior to founding AMFitzgerald, Fitzgerald worked at the Jet Propulsion Laboratory, Orbital Sciences Corporation, Sigpro, and Sensant Corporation, now part of Siemens. She received her bachelor’s and master’s degrees from MIT and her doctorate from Stanford University, in Aeronautics and Astronautics. Fitzgerald has numerous journal publications and holds eight patents. She served on the Governing Council of MEMS Industry Group from 2008-2014 and was inducted into the MIG Hall of Fame in 2013. Fitzgerald serves on the Board of Directors of both Rigetti Computing and the Transducer Research Foundation.