The Cutting Edge: COMPUTING / TECHNOLOGY / INNOVATION : Device Looks Like a Chip, Works Like a Robot--and Fits on a Fingertip : Micromachines: Global market is expected to explode to nearly $14 billion by 2000.
They will make it possible to analyze a blood sample in an instant, or warn a driver if he is on a collision course with another car, or adjust the tempo of a heart pacemaker. They might help coffee connoisseurs steam a better froth of milk for their lattes or tell skiers how many vertical feet they covered in a run.
They are micromachines, devices so tiny they fit on a fingertip but pack the power of much larger machines. More like computer chips than tiny robots, micromachines have already become staples in a handful of products--and industry executives say they’ll soon be found in a whole lot more.
About 10 companies, mostly clustered around the Silicon Valley, are rapidly transforming their devices from laboratory novelties into practical consumer products. The market for micromachines, worth just $1 billion worldwide in 1994, is expected to explode to nearly $14 billion by 2000, according to System Planning Corp., an engineering consulting firm based in Arlington, Va.
“People are suddenly realizing they can micromachine very small chips for numerous kinds of applications,” said Kurt Petersen, vice president of Lucas Novasensor, a Fremont, Calif., company that manufactures nearly a million micromachine sensors a month. “Different industries are all picking it up for different applications, from medical to automotive to aerospace to robotics to even toy companies.”
Today, medical and automotive uses account for nearly three-quarters of the micromachine market. But that proportion is expected to shrink in the next five to 10 years as the chip-like devices make their way into products like flat-panel television screens, disk drives and super-high resolution color printers.
There was a time just a few years ago when micromachines were seen as yet another area in which the technical breakthroughs of U.S. researchers were going to be exploited commercially by Japanese corporations. Japan’s Ministry of International Trade and Industry made a major investment in micromachine technology in the early 1990s, and U.S. companies appeared to have little interest.
But the Japanese have focused on building tiny machines with tiny machine tools, essentially creating miniature versions of conventional machines. While the theory holds great promise, the practical problems of economically creating useful devices in this fashion are daunting, said Kerry Kachejian, System Planning Corp.’s technical director.
U.S. firms, by contrast, have concentrated on specific types of devices that can be fabricated like computer chips--namely sensors and accelerometers that measure pressure or acceleration and can be used in the place of bulky pumps or magnets. And the niche-market nature of the earlier micromachine applications is better suited to small high-tech firms in America than to gigantic Japanese corporations.
“Where Japanese culture and organization works well is not a great match with micromachines,” said Jim Kneutti, president of Silicon Microstructures, which makes sensors in Fremont. “Take a 1-million-piece market. At $2 apiece, that’s a $2-million market. That’s great for us, but not for Toshiba.”
Most of those $2 million-a-year markets at the moment are in the automotive and health fields. Abbott Laboratories, for example, uses Lucas Novasensor’s pressure sensors to build the Transpac, a 1-by-2-inch box that attaches to the end of a catheter tube and measures blood pressure in the heart of an acutely ill patient.
“In the old days, you used a reusable device which had to be cleaned and sterilized between patients,” said Harlow Christianson, a senior technical member of Abbott’s hospital products division in Mountain View, Calif. “With micromachines, you use a fresh new disposable (Transpac) for a fraction of the cost.”
Kneutti says Silicon Microsystems, whose 3-year-old company also makes sensors to measure blood pressure, will sell nearly a million of the sensors this year for about $2 each.
An accelerometer, another kind of micromachine that senses changes in acceleration, is the key to the “smart pacemaker.”
“If you’re moving around a lot, like when you’re jogging, the pacemaker can detect that motion and pace the heart faster,” Petersen explained. “If you’re in bed asleep and not moving, it paces the heart a lot slower.”
With a few modifications, the same accelerometer can detect an impending car crash and tell an air bag to inflate. Air bag sensors are already the biggest market for micromachine devices, and demand will be even stronger when driver-side air bags become mandatory for all cars sold in the United States in 1998.
Engineers at Siemens Automotive in Auburn Hills, Mich., used a micromachine sensor as small as a dime to improve their air bag system. The sensor replaced a complicated set of three-inch-square sensors distributed throughout a car and connected by cables. The new system costs about half as much as the old system and is 10 times less likely to break, said Bert Wolfram, the program manager for Siemens’ passenger safety system.
Siemens supplies air bag systems to General Motors, Ford, Volkswagen, Suzuki and Hyundai. Wolfram’s group is now designing the next generation of front- and side-impact air bags.
“We want to make the system smarter, and with micromachine sensors, we have that possibility,” he said. “For example, we can read whether someone is wearing his seat belt and deploy the air bag in a different way. We could detect whether there’s a rear-facing child seat in the passenger seat and shut the air bag off. We could even sense whether there’s a small female versus a big guy who used to wrestle and deploy the air bag faster or softer.”
Engineers at Delco Electronics are adding accelerometers and micromachine yaw sensors to Forewarn, a radar and computer system that flashes a warning icon to a driver who is about to crash. Around the country, others are working to incorporate micromachines into every facet of an automobile, from its suspension system to fuel injection. By the turn of the century, every new car will have at least five, the micromachine experts say.
More medical products are on the way, too. Redwood Microsystems has patented a micromachine actuator called a Fluistor that can control the delivery of fluids and gases when combined with a pressure sensor, said Ben Dehan, marketing director for the Menlo Park, Calif., company. Within the next three years, Fluistors will have several jobs in operating rooms, from monitoring a patient’s anesthesia to keeping the abdomen inflated while surgeons are making incisions there, he said.
Silicon Microstructures is working to build a “lab on a chip” that will analyze body fluids, though it’s still five or six years away.
“You’d go into a doctor’s office, put a blood sample on this thing and get an instantaneous reading of what’s in there,” Kneutti said. “Now that normally takes a couple of days and lot of expense in a hospital laboratory.”
And then there’s the high-tech coffee.
“We picked up a job a week ago to make a sensor that goes inside a coffee machine and controls the water pressure so you don’t have to stay in the kitchen to make cappuccino noises,” Kneutti said.
That’s just one of many consumer products that engineers say can be made better in years to come as micromachines become more sophisticated. The versatility of the devices will insure the industry’s survival, Kachejian said.
“There are dozens, if not hundreds, of applications for micromachines,” he said. “There will always be two new ideas to replace an old idea that died.”
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Big Workers
Micromachines are fabricated in much the same way as integrated circuit computer chips. Computers are used to design a micromachine device. A shrunken image of the device is photographically etched onto a silicon wafer. The wafer is then bathed in an acid to wash away layers of silicon. What’s left is a tiny machine--usually smaller than five square millimeters--such as a pressure sensor or an accelerometer.
Accelerometer
An accelerometer consists of three layers of silicon. In the center of the middle layer is a mass, supported by four beams with resistors. When a force, such as acceleration is applied, the mass is displaced, putting a strain on the supporting beams. The resistors in the beams measure the amount of displacement, which in turn can be used to calculate the acceleration.
Pressure Sensor
The top layer of a pressure sensor is made from silicon, and the middle is etched out until only a thin membrane remains. When the pressure on the system changes, the silicon membrane bulges out or sinks in slightly. Resistors on the top layer of silicon measure this deflection and use that to calculate the change in pressure.
Source: IC Sensors, System Planning.
