In the air and on the ground
09/01/2007
MEMS and nanotechnology are solving challenges in defense and security applications-and promise to further change military and aerospace operations in the future
BY COURTNEY E. HOWARD
There is tremendous potential in nanotechnology and related disciplines to have a very positive impact on our future,” says Dr. Les Kramer, director and chief technologist at Lockheed Martin Missiles and Fire Control in Dallas, Texas. “For example, weapons will become smaller, lighter, and smarter. Electronics will shrink in size, but [will] have greater capabilities and memory. Sensors will see farther, with greater resolution.”
MEMS and nanotechnology have bred products useful in today’s military and aerospace environments. MEMS, for instance, have contributed to the production of micromachines, micro-integrated circuits, and micro-optics used in the defense, security, and aerospace sectors. LADAR/LIDAR, infrared cameras, miniature unmanned vehicles, target-recognition devices, head-mounted displays, robotic-guidance systems, night-vision goggles, reconnaissance systems, thermal imagers, and friend/foe identification solutions benefit from MEMS.
Nanotechnology benefits the design and development of miniature chemical and biological sensors, flexible and wearable displays, portable X-ray devices for medical use and cargo inspection, and RF amplifiers for radar, communications, and electronic countermeasures.
NASA engineers are eliciting the help of MEMS and nanotechnology in the creation of smart sensors and probes, overall system miniaturization, autonomous spacecraft, microspacecraft, micro- or nano-rovers for planetary exploration, and compact, low-power, high-performance computing platforms.
MEMS in space
Although Dr. Keith Ortiz, manager of the MEMS Technologies Department at Sandia National Laboratories in Albuquerque, N.M., cannot discuss current defense projects due to the nature of Sandia’s work, he can reveal information about Sandia’s delivery of MEMS-based microshutters to the Johns Hopkins University Applied Physics Laboratory for NASA’s Space Technology 5 (ST5) mission-the first MEMS to fly in space.
NASA engineers working on the ST5 satellites were concerned about severe temperature fluctuations affecting the performance and longevity of the onboard electronics. Sandia MEMS designers worked with researchers at the Johns Hopkins University Applied Physics Lab in Baltimore to help develop a MEMS-based microsatellite thermal-control solution. In addition to using Sandia’s SUMMiT V technology, the device incorporates a moving grillwork of shutters with slats that measure 6 microns wide and 1,800 microns long. (A human hair is about 100 microns thick.) Electrostatic actuators move the shutters back and forth to manage heat transfer through the satellite’s skin.
“This is the first time a space-qualified device of this type has ever been flown [in space], and the first to be flown on the outside of a satellite,” says Ann Darrin, program manager at the Johns Hopkins Applied Physics Lab.
 Research engineers at the Army’s Natick Soldier Center are using MEMS technologies and nanotechnology to benefit the Future Force Warrior, shown here. |
The NASA ST5’s three orbiting microsatellites, which have completed their three-month mission, incorporate a wealth of MEMS technologies and nanoscience. Each fueled satellite, approximately the size of a 13-inch television, weighed about 55 pounds when launched, employed a single microthruster the size of a quarter, measured the magnetic field using miniature magnetometer, and used miniature spacecraft radio transponders for space-to-ground communications and tracking.
The project, which was developed and tested at Goddard Space Flight Center in Greenbelt, Md., is part of the New Millennium Program, managed for NASA by the agency’s Jet Propulsion Laboratory, in Pasadena, Calif. The program involves the development and testing of technologies that provide future science mission capabilities with a high payoff and reduced cost and risk.
“I’m kind of in awe that these MEMS devices are in space,” says Sandia researcher Jim Allen. “It’s a cool milestone for MEMS devices.”
 Sandia researcher Jim Allen inspects a MEMS device that features a moving grillwork of shutters with slats that are 6 microns wide and 1,800 microns long. |
“We are only beginning to realize how these new developments may find practical applications,” says Ortiz. “The next wave of MEMS applications will be enabled by dense integration of MEMS devices. The microshutters are a simple example of what is possible.”
Powerful stuff
Miniaturized systems require small and robust power supplies, yet packing sufficient fuel in a tiny form factor is not an easy feat. mPhase Technologies has developed-with help from a cooperative research and development agreement (CRADA) from the U.S. Army Armament Research, Development, and Engineering Center (ARDEC) at Picatinny Arsenal, N.J.-a miniscule battery.
Army researchers are evaluating the mPhase Smart Nano battery and ultrasensitive magnetometer prototypes using the Army’s testing facilities at Picatinny Arsenal to potentially incorporate the technologies into programs sponsored by Picatinny.
 The development team at mPhase Technologies has engineered a smart nanobattery, which is being evaluated by staff at Picatinny Arsenal, N.J. |
Potential defense applications for the mPhase magnetometer are perimeter security applications and navigation in “GPS-denied” environments. The Smart Nano battery could aid military efforts by powering small electronics, such as sensors, and small guided and smart munitions.
Initial tests indicate that the nanostructure of the prototype power cell and magnetometer demonstrated resiliency to shock and acceleration, surviving a test that subjected them to acceleration at a g-force of 12,000.
Accelerating MEMS
Another CRADA-this time between Omega Sensors Inc. and the Space and Naval Warfare Systems Center (SSC), Office of Research and Technology Applications, both in San Diego, Calif.-is helping to advance MEMS technologies.
The Omega Sensors team is collaborating with scientists and engineers at SSC San Diego on the development of applications for the company’s MEMS ultra-sensitive accelerometer (MEMSUSA) technology. MEMS accelerometers measure acceleration and movement in navigational vehicles, such as helicopters and airplanes, but are typically very expensive, priced in the range of tens of thousands of dollars.
Omega Sensor’s MEMSUSA accelerometer combines Fabry-Perot interferometer technology with MEMS technology. “The advantage of MEMS is a low-cost structure,” explains Brad Chisum, president of Omega Sensors. “We’re able to the deliver high-cost performance, meaning up to $17,000, at the MEMS pricing level, which is less than $100, even at low production levels. This gives us a huge advantage.”
MEMS accelerometers could be used in guided missiles, unmanned ground, aerial, and underwater vehicles, and for monitoring the condition of helicopters and submarines by measuring their vibration. “If that vibration is beyond a certain threshold, then it is due for maintenance,” Chisum says.
Chisum has received funding to complete a third-generation prototype from the Center for Commercialization of Advanced Technology (CCAT) at San Diego State University. Omega Sensors received a $75,000 prototype development, test, and evaluation (PDT&E) award from CCAT San Diego, and additional funding from the Defense Advanced Research Projects Agency (DARPA) in Arlington, Va.
Due for release in the fall, the next-generation prototype will go beyond the MEMS accelerometer, adding navigational gyroscopes and multi-access accelerometers capable of measuring acceleration in multiple directions. “Navigation requires multiple accelerometers,” Chisum notes, “and integrating them on the same chip cuts the cost and size of the chip.”
The CCAT program seeks technologies engineered by government labs, academic researchers, and small entrepreneurs, and helps guide them through the technology transfer process and into the hands of warfighters, first responders, and security personnel.
The Omega Sensor accelerometer is expected to come to market within three years.
Powering nanodevices
As ingenious as today’s miniature devices are today, they still require bulky power supplies or fuel systems-negating some innovative work in various areas, such as unmanned vehicles. Yet work at Georgia Tech in Atlanta might be just the thing to free the nanomachine from the monkey (or batteries) on its back.
A team of researchers-including Xudong Wang, Jinhui Song, Jin Liu, and Zhong Lin Wang, a Regents professor in the Georgia Tech School of Materials Science and Engineering-has developed a nanogenerator that converts motion into electrical current. The nanogenerator is an array of tiny filaments-zinc oxide nanowires-that produces continuous direct-current electricity from mechanical energy. Safe enough for use in biomedical applications, the nanoscale generator could generate energy from internal vibrations and even blood flow.
 A prototype direct-current nanogenerator was developed by Georgia Tech researchers using an array of zinc oxide nanowires. |
“If you had a device like this in your shoes when you walked, you would be able to generate your own small current to power small electronics,” says Wang. “Anything that makes the nanowires move within the generator can be used for generating power. Very little force is required to move them.”
The nanogenerator is expected to produce as much as four watts per cubic centimeter, sufficient power for nanometer-scale defense, environmental, and biomedical devices. Potential applications include powering nanomotors, biosensors implanted in the body, environmental monitors, and nanoscale robots.
The researchers developed the nanogenerator with the support of the National Science Foundation, DARPA, and the Emory-Georgia Tech Nanotechnology Center for Personalized and Predictive Oncology.
Infused with investments
Technology companies continue to make investments into the research, development, and production of MEMS and nanotechnology innovations. Product releases in the nanotechnology area, especially, are critical to the future of the science. It is often said that people don’t buy technology; they buy products. It keeps investor confidence high and holds the interest and funding of federal governments, where impatience can often kill a field of study. This is the challenge of today’s MEMS and nanotechnology firms, the managers of which are staying the course for the long term and continuing to invest in the technologies’ future.
“The investment in creating a MEMS capability is substantial,” says Sandia’s Ortiz. “The potential payoff to national security is worth the investment. As it has in the past, Sandia will continue to work with industry and government to enable military and aerospace applications of MEMS.”
Also seeing promise in MEMS, executives at N.Y.-based API Nanotronics Corp. are opening a MEMS fabrication facility dedicated to the manufacture of sophisticated electronic components for the defense industry. “What we have heard from our military customers is, ‘We want to do this, we want to do that, we want to do it smaller,’ ” says Thomas Mills Sr., API Nanotronics’ president and chief operating officer.
Overseeing the project is the company’s newly appointed chief technology officer, Martin Moskovits, who played a role in establishing the five nanocenters of the U.S. Department of Energy as a member of its Basic Energy Sciences Advisory Committee.
“There’s a great deal of spending going on right now in R&D,” Moskovits adds. “For example, DARPA has a program called HERMIT [harsh-environment robust micromechanical technologies] that funds a great deal of research in MEMS technologies for the defense sector.”
Similarly, mPhase Technologies in Little Falls, N.J., formed AlwaysReady Inc., a wholly owned subsidiary dedicated to nanotechnology and MEMS-based products, and to transform homeland security and other markets. AlwaysReady currently offers two solutions for defense applications, such as detecting bombs or metal guns: a smart nanobattery capable of producing current-on-demand after long-term storage, and a family of uncooled magnetometers, including ultrasensitive versions.
“These products can save lives,” says Ron Durando, president and CEO of mPhase Technologies. “In the coming years, the nanotechnology category will evolve into a trillion-dollar industry. The world has changed, and we must change with it.”
This article was adapted from Military & Aerospace Electronics magazine (www.mae.pennnet.com).
Courtney E. Howard is senior editor of Military & Aerospace Electronics magazine, a sister publication of Small Times.