It turns out Walt Disney was right. It is a small world after all. At least, the world where micro-electromechanical systems (MEMS) operate, is very small. Their impact, however, is quite large and growing rapidly.
The idea of MEMS is not new. They are created by combining several other technologies, including sensors, actuators, mechanical elements, and electronics. What has changed over the years is their size — they’ve gotten smaller and smaller. At the same time, their capabilities have increased greatly.
Today, MEMS are revolutionizing nearly every product category by bringing together silicon-based micro-electronics with micro-machining technology.
Let’s examine some of the newer MEMS applications, which illustrate some of the benefits these devices are now delivering and how they truly are transforming just about every industry. As a result, our lives are being enriched in ways that were unimaginable just 20 years ago.
Just consider the field of medicine. As recently reported in MIT Technology Review, Medtronic, the world’s leading medical-device maker, is working on a pacemaker smaller than a Tic Tac mint; it should be available within five years.1
By contrast, current pacemakers are about the size of a silver dollar. A key benefit of this greatly reduced size is that the device would eliminate lead wires since it could be positioned right where the electricity is needed. These wires cause a pacemaker to require greater power; plus, if they fail, there can be serious complications.
Another cardiovascular application was highlighted in a study at the University of Southern California.2 It showed that a MEMS thermal sensor can detect the earliest stages of atherosclerosis, a form of cholesterol build-up on the insides of arteries.
The sensor moves through the arteries using an angiogram catheter. If it detects a slight change in a voltage signal in an area of the artery that otherwise shows no clinical signs of atherosclerosis, it notifies the doctors.
Once this area of the artery is identified, the doctor can decide if the region warrants treatment or not. Early treatment can prevent future heart attacks and strokes.
For diabetics, there’s potential good news coming out of the University of Calgary. The school’s MEMS laboratory has patented a skin patch that offers a less-invasive, and therefore less painful, way to take blood samples.3
Called the “Electronic Mosquito,” it consists of four electronically controlled micro-needles that only penetrate deep enough to draw blood, but not enough to hit a nerve. Sensors measure sugar levels, sending the information wirelessly to a remote receiver.
Another promising medical device based on MEMS technology is a prototype model of an implantable artificial kidney.4 For the 85,000 patients on the kidney transplant waiting list, and the 350,000 on dialysis, it will be life-changing.
With the rapid advancement of MEMS, there’s no doubt that someday soon implantable artificial kidneys will be a reality. The goal of the University of California San Francisco researchers is to create a device that is the size of a coffee cup.
It will use thousands of microscopic filters and a bioreactor that will serve the metabolic and water-balancing roles of a real kidney. A larger external model has proven that the idea works, so work is now underway to reduce it to an implantable size.
For some MEMS applications, internal computing power is required. The incredibly small scale of this type of computer defies the limits of traditional semiconductor materials.
But now, a team from Harvard and MITRE’s nanosystems group may have broken this smallness barrier with a reprogrammable circuit made out of nanowire transistors.5 Keep in mind that a nanometer is one-billionth of a meter, and nanowires tend to be only 30 to 60 nanometers wide, making this undeniably the smallest computer in the world.
This microcomputer contains only 496 transistors, but if Moore’s Law continues its relentless advance, that number will double every 12 to 18 months.
For people who don’t work in a micro-scale environment, it would never occur to them how challenging it is to manipulate such tiny objects. An engineering research team from the University of Waterloo understood this challenge and devised flying micro-robots that now give researchers more control in this environment.6
Powered and levitated by a magnetic field, these robots use micro-grippers to move tiny objects with far greater precision. Applications for these micro-robots may include micro-assembly of mechanical components, handling of biological samples, and even microsurgery.
As MEMS technology continues to evolve and improve, we foresee the following four developments:
First, many new business opportunities will arise. As MEMS technologies advance, they are opening up a whole new uncharted frontier of opportunities for harnessing the power of these small devices. The limit will only be how creatively entrepreneurs think. There will be opportunities not only in the application of devices, but also in improving manufacturing techniques and the design of MEMS.
Second, MEMs will improve medical diagnostics, helping to pave the way for the disruption of the health care industry that we explored in our discussion of The Coming Revolution in Medical Business Models trend. For example, research scientists at the Fraunhofer Institute in Dresden, Germany are developing a microscopic image sensor that promises to accelerate cancer diagnosis by speeding up the detection of tumors.7 Fitted to the tip of an endoscope, this sensor is just eight millimeters in diameter, which allows it to be inserted into the body through minimally invasive surgery. By providing magnifications down to the cellular level, this technology can make accurate diagnoses of cancers in real time. This eliminates the time-consuming need to remove tissue and examine it under a microscope, as well as the stressful wait by patients.
Third, many industries will be transformed in ways that are almost impossible to imagine today. Consider the winemaking industry. In growing grapes to make wine, one of the challenges vintners face is achieving the precise balance between drought and over-watering. Either extreme will diminish the quality of wine grapes. To help growers maintain a perfect level of soil moisture in the vineyards, a team from the Cornell Nanofabrication Facility in Ithaca is developing a microsensor that can be embedded in a vine and will measure in real time the water stress in the plant.8 This sensor will transmit its reading wirelessly to a central server, where the data will be summarized for the grower. The team hopes that micro-manufacturing will bring down the cost of the device to allow even the owners of small vineyards to benefit from the technology. Of course, grapes aren’t the only crop that could benefit from such a breakthrough. Microsensors could be used throughout the agriculture industry to conserve water and boost crop yields.
Fourth, MEMS technologies will ultimately bring improvements to many consumer products, from cell phones to cars. A perfect example is the new microprojector from Lemoptix that is so small it can be integrated into a portable computer, a mobile telephone, or even an MP3 player.9 Anticipated to be on the market at the end of 2011, this device can project an image equivalent to a 15-inch screen at a 640 by 480 resolution. The projection head is only one cubic centimeter and contains tiny mirrors that reflect red, blue, and green laser beams. There will be many applications for this technology beyond simply projecting videos from your cell phone. The auto industry, for example, could use this technology to display a car’s speed or GPS information directly onto its windshield, much like a heads-up display in a fighter plane.
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