A new take on MEMS innovation


by Marlene Bourne, contributing editor

With three of the key end markets for MEMS devices currently struggling (auto sales are down, the inkjet market is shrinking, and LCD has all but edged out DLP TVs), I find it especially interesting that current emerging market drivers aren’t necessarily coming in the form of new MEMS devices as in the past, but rather new ways to apply existing MEMS devices. Even better, all of the following examples offer real potential for very high unit volumes.

Let’s start with pressure sensors, which got the MEMS industry on a roll some three decades ago when they revolutionized automobiles and blood pressure. In 2007, MEMS pressure sensors (for use in industrial automation alone) accounted for nearly 40% of overall MEMS revenues, or more than $3.2 billion. But what made news this past year was a resurgence of interest in pressure sensors in medicine. CardioMEMS’ implantable pressure sensor for cardiovascular monitoring is certainly impressive, and even more so as the product family is expanded to include hypertension, a significantly larger market.

Now a second, equally exciting application is emerging: glaucoma. Early this year the U. of Washington created considerable buzz with a contact lens embedded with micromachined electronics. Lost in the noise over the incredibly exciting potential of “bionic eyes” was the introduction of a contact lens embedded with a real, working sensor. Developed by Sensimed, the soft, disposable contact lens (containing a pressure sensor, microprocessor, and antenna) provides real-time monitoring of intraocular pressure, and could potentially save the eyesight of millions.

Photo courtesy: University of Washington
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Another emerging application for pressure sensors is medical patches. Why it’s taken this long for engineers to consider pairing sensors with basically Band-Aids is beyond me, but I was excited to see a number of really cool efforts publicized in 2008. The first, from IMEC, is a battery-free, wireless EEG patch. One of the most unique aspects of this product is the fact that it’s powered by both body heat and ambient light. Heat dissipated from a person’s temples (where the patch is worn) is detected by tiny MEMS thermopiles, which work in conjunction with silicon photovoltaic cells. The main system (the part which collects and analyzes the data) looks like a set of headphones.

Toumaz Technology is taking things a step further with its Sensium digital bandage, which can interface with and switch between three different sensors (e.g., a tri-axis accelerometer, blood glucose sensor, pH sensor, pressure sensor, and/or electrocardiogram), although it can only measure one parameter at a time. Even more intriguing is the use of a printed zinc battery, which has a 5-7 day lifespan. I believe the thin-film battery is from Power Paper, which made its debut several years ago in an anti-wrinkle patch from Est??e Lauder.

Photo courtesy: Toumaz Technology
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Accelerometers are a mainstay of the MEMS industry, and their use in automotive airbags is probably the most well-known application. Despite the fact that they’re now beginning to proliferate in consumer electronics (which I’ll address a little bit later), airbags and other accelerometer-based safety systems are moving from cars to, of all things???bikes! Thanks to some hilarious video, Dainese got a lot of attention recently for a wearable airbag system they developed for motorcycle racers. Although similar items made the news some years back, this is perhaps the most advanced, and protective, product yet. The D-Tec system was demonstrated at a race in Italy and is expected to hit the market (no pun intended) in 2010.

When it comes to safety, who says that big companies have all of the good ideas? A student at the U. of Massachusetts/Amherst recently developed the “wireless impact guardian” (WIG), or what he calls the “OnStar of Helmets.” Embedded in the bike helmet are an accelerometer (to detect impact) and a GPS-based system (to provide location for rescue crews). Upon impact, the helmet will sound an alarm; if the wearer doesn’t turn it off, WIG sends for help. A start-up has been formed to further develop the product for use by motorcyclists, ATV enthusiasts, and even casual bicyclists. This last category in particular could resonate on a mass level, with parents???not only for physical protection against head injury, but potentially as a way to keep track of their child’s location. GPS is being embedded fairly quickly into school uniforms, so bike helmets aren’t too far of a reach.

Elder care: The next big MEMS market?

Gyro sensors hit it big these past few years in automotive safety, but even with their now-mandated inclusion in all passenger vehicles in the US as the core of anti-rollover systems, the dramatic decline in auto sales this past year makes the market less attractive, at least in the short term. However, one emerging end-use could eventually rival the automotive market: elder care.

Photo courtesy: Honda
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Raytheon received a lot of attention earlier this year for its Exoskeleton technology, which formed the basis of the recent blockbuster movie Iron Man (and if you missed it, be sure to rent it). What the media missed was a concurrent announcement by Honda about a scaled-down version (which relies on MEMS sensors) to assist those who have difficulty walking.

It’s a far cry from a “super strength-boosting” full-body exoskeleton, but Honda’s “walking assist device” employs a similar approach and the same technology used in its ASIMO robot. The device obtains information from hip angle sensors (i.e. gyros) to help keep its wearer upright, and its motors increase the wearer’s natural stride???this, Honda says, should make the device ideal for the elderly or those with weakened leg muscles. It was originally showcased as a prototype, but I imagine this will become a commercial product fairly quickly, especially since several other companies have recently announced similar products, one of which was heralded as a way to make a former paraplegic walk.

With a rapidly aging population worldwide, the implications are potentially profound in terms of helping the elderly maintain their independence. It’s a far bigger market with arguably a greater need. Which scenario would you prefer: shuffling along with a walker, or being able to maintain an upright posture? Dean Kaman may have set out to transform transportation with the Segway, but I suspect this approach may go much farther in that respect.

Lab-on-a-chip and micromachined cantilevers have been in development by any number of companies over the years as a way to create tremendously sensitive biological and chemical sensors. Interest in both seems to ebb and flow, and companies have come and gone. However, Microvisk Technologies is taking a completely different approach: specifically targeting patients who are taking anti-coagulant drugs, i.e., blood thinners. If you’ve had a heart attack, you took blood thinners at some point, and maybe still are. The way in which Microvisk’s technology measures blood viscosity (as a way to maintain the correct dosage of anti-clotting medication) is simple: the degree and speed in which the cantilever bends indicates the thickness of the blood.

In terms of potential market, not only is an aging global population in play here, but so is the increased incidence of obesity???both of which are leading to a rise in the number of heart attacks, and thus the number of people who could potentially benefit. More product development is necessary, and it’s not known who would use the device (patients or physicians). But this is certainly a new way of applying both lab-on-a-chip and micro-cantilever technology that, in my opinion, uniquely meets an unmet and growing market need.

A MEMS materials movement

Let’s switch gears, and look at how the innovative use of materials is opening the door to applying existing MEMS device technology in new ways. Few companies have successfully commercialized MEMS switches. There are a number of reasons why, but perhaps the issue lies in the choice of material used. Maybe silicon isn’t the answer???so, how about plastic switches instead?

Last year, researchers at the U. of Tokyo revealed the development of thin, flexible sheets of plastic that can transmit electrical energy to nearby objects, without the need for direct electrical contact???imagine a plastic tablecloth with Bluetooth-like capability. Even more intriguing is the fact that one layer of this plastic material is an array of plastic MEMS switches; the other layers consist of inkjet-printed organic insulating and semiconducting materials, as well as metal nanoparticles (which act as transistors). This certainly offers some very intriguing possibilities, most notably for wirelessly powering consumer electronics, smart appliances, sensors, and other similar devices within the home.

Photo courtesy: Microvisk Technologies
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Speaking of nanoparticles, it seems to me that one of the highlights of 2008 will be the number of breakthroughs pertaining to the use of various nanomaterials to enhance magnetic resonance imaging (MRI) techniques. The obvious benefit is allowing doctors to see what they couldn’t before. However, did you know that MEMS might factor in here at some point in the not-too-distant future?

One brand-new MEMS device in this field really caught my attention this past year. Researchers at NIST have created tiny micromachined magnets with a physical shape that provides for a precisely tunable RF signal, and thus creates images simply by moving water through and around the structures. Even more interesting is the fact that the signals can be converted into color. Each micro-magnet consists of two round, vertically stacked discs a few microns in diameter and separated by an air gap. The magnetic field for each micro-magnet can be customized by changing the material, adjusting the gap between the discs, or changing the discs’ thickness or diameter.

Photo courtesy: U. of Tokyo
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From color images, we turn to inkjet printing, a market that continues to struggle???which is big news for the MEMS industry, since inkjet printing has historically accounted for a significant percentage of total revenues. Companies in this sector have not shifted into industrial applications as was originally envisioned several years ago. However, if a patent I came across last year actually comes to fruition, inkjet printing could become bigger than ever.

Photo courtesy: NIST
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This all hinges on an “electrostatic spraying device” being jointly developed by Matsushita and Procter & Gamble, which uses inkjet printing technology to apply color cosmetics to the face. (Men might snicker and dismiss this, but the market potential is staggering.) Consider this: a removable cartridge is filled with liquid color cosmetic such as foundation, eyeshadow, or lip gloss, and then placed into a small, handheld, battery-operated printer (about the size of a cell phone) which then “prints” the cosmetic onto the face. It works very much like the airbrushing systems used by professional make-up artists, which provide fantastic results but are expensive. However, sell these disposable cartridges of cosmetics for a few dollars each and we’re talking about the potential for hundreds of millions of units on an annual basis. This business model is a goldmine that could rival and potentially vastly exceed today’s inkjet printing market, and successfully transition an important MEMS segment at the same time.

MEMS accelerometers: Finding the selling point

Lastly, I’ve voiced very strong resistance over the past couple of years about how quickly (and widely) cell phones would integrate MEMS accelerometers, because I’ve long felt that novel functionality alone just wasn’t enough; the sensors were an unnecessary cost that didn’t provide any real value to the handset manufacturers. However, late this summer, I finally identified what I believe will truly drive the integration of MEMS accelerometers: fee-based software and other third-party applications.

By directly tying an accelerometer to revenue generation, cell phone manufacturers now have a compelling reason to integrate these sensors into all handsets, even the low-cost ones. It’s not enough to say that cell phones will drive accelerometer growth (it’s obvious they even-tually would); what’s important is being able to identify why.

Fullpower Technologies’ release of MotionX Poker, as well as the staggering number of downloads from Apple’s Apps store in such a short period of time???and the revenue share involved???is what made the light bulb go off for me. It certainly didn’t hurt that the big boys, Sega and Electronic Arts, revealed the creation of their own gaming applications that are accelerometer-based. And never mind the potential for other kinds of fee-based applications/services that could leverage the accelerometer (such as GPS maps and health monitoring). This is innovation at its best.

What’s key here is that both the software developers and the handset manufacturers (in this case Apple) are making money from the sensor. My reasoning was cemented by the announcement of Google and T-Mobile’s Android store, their answer to Apple. It’s clear we’ve hit an incredibly important turning point. Now the case can be made for accelerometers.

I recently saw an article in which Yole Développement admonished the MEMS industry for not sufficiently pursuing the cell phone market and letting opportunity pass them by. I completely disagree. MEMS suppliers weren’t missing an opportunity???there was no market. The desire to integrate MEMS accelerometers into cell phones has been the most blatant cases of technology push I’ve ever seen.

To their credit, MEMS suppliers were trying hard to create market demand, but as I’ve stated repeatedly, unless you can tie revenue to that sensor, the additional cost made absolutely no sense. Over the past several years I’ve questioned the lack of value-add, and pointed out the need for a Trojan horse???a backdoor approach to cell phones that would provide a compelling reason why the cell phone manufacturers needed to add that sensor, and its associated cost, no matter how rapidly its price was falling.

Money???now that’s a reason for market pull. And it’s emerging in the form of something completely foreign to the MEMS industry: software.

For consumer electronics, the sensor is simply a means to an end. This market is all about software, whether it’s software drivers or fee-based applications???something I identified nearly three years ago as a critical factor that the MEMS industry was overlooking The smart players have not only been talking with the software developers, but adding software developers to their staff. They have to???it’s not only emerging as a critical driving force behind continued MEMS innovation, but increased competitiveness as well.

Marlene Bourne is president and principal analyst of Bourne Research LLC. She can be reached at