MIT researchers are putting a tiny gas-turbine engine inside a silicon chip about the size of a quarter. The resulting device could run 10 times longer than a battery of the same weight can, powering laptops, cell phones, radios and other electronic devices.
It could also dramatically lighten the load for people who can't connect to a power grid, including soldiers who now must carry many pounds of batteries for a three-day mission -- all at a reasonable price.
The researchers say that in the long term, mass-production could bring the per-unit cost of power from microengines close to that for power from today's large gas-turbine power plants.
Making things tiny is all the rage. The field -- called microelectromechanical systems, or MEMS -- grew out of the computer industry's stunning success in developing and using micro technologies. "Forty years ago, a computer filled up a whole building," said Professor Alan Epstein of the Department of Aeronautics and Astronautics. "Now we all have microcomputers on our desks and inside our thermostats and our watches."
While others are making miniature devices ranging from biological sensors to chemical processors, Epstein and a team of 20 faculty, staff and students are looking to make power -- personal power. "Big gas-turbine engines can power a city, but a little one could 'power' a person," said Epstein, whose colleagues are spread among MIT's Gas Turbine Laboratory, Microsystems Technology Laboratories, and Laboratory for Electromagnetic and Electronic Systems.
How can one make a tiny fuel-burning engine? An engine needs a compressor, a combustion chamber, a spinning turbine and so on. Making millimeter-scale versions of those components from welded and riveted pieces of metal isn't feasible. So, like computer-chip makers, the MIT researchers turned to etched silicon wafers.
Their microengine is made of six silicon wafers, piled up like pancakes and bonded together. Each wafer is a single crystal with its atoms perfectly aligned, so it is extremely strong. To achieve the necessary components, the wafers are individually prepared using an advanced etching process to eat away selected material. When the wafers are piled up, the surfaces and the spaces in between produce the needed features and functions.
Making microengines one at a time would be prohibitively expensive, so the researchers again followed the lead of computer-chip makers. They make 60 to 100 components on a large wafer that they then (very carefully) cut apart into single units.
Nancy Stauffer, Laboratory for Energy and the Environment
Photo / Donna Coveney
An MIT researcher has a vision: Four hundred huge offshore wind turbines are providing onshore customers with enough electricity to power several hundred thousand homes, and nobody standing onshore can see them. The trick? The wind turbines are floating on platforms a hundred miles out to sea, where the winds are strong and steady.
Eliminating gender bias in universities requires immediate, overarching reform and decisive action by university administrators, professional societies, government agencies, and Congress. Women face barriers to hiring and promotion in research universities in many fields of science and engineering -- a situation that deprives the United States of an important source of talent as the country faces increasingly stiff global competition in higher education, science and technology, and the marketplace, says a new report from the National Academies.
An IBM-led (NYSE: IBM) consortium, the newly formed 
In an effort to provide safer and more reliable components for aircraft, researchers have invented an optical on-off switch that can replace electrical wiring on airplanes with fiber optics for controlling elevators, rudders, and other flight-critical elements. Fiber-optics technology has already transformed life on the ground by replacing copper wire to transmit voice calls, Internet traffic, and other telecommunications. Now, engineers are preparing an important new fiber-optics application for liftoff, with their prototype switch ready for testing on real-life aircraft. The technology also has potential applications on the nation's highways, as a "weigh-in-motion" sensor for measuring the weight of fast-moving commercial trucks without requiring them to stop on a scale. The research is described by Zhaoxia Xie and Henry F. Taylor of Texas A&M University in the current issue of Optics Letters, a journal of the Optical Society of America.
The National Science Foundation’s Cyber Trust Program has awarded Stevens Professor K.P. (Suba) Subbalakshmi a grant to further her research on wireless network security, in particular, the fundamental trade-offs in wireless security, power consumption and error-resilient encryption code design. Subbalakshmi, an Assistant Professor in Stevens’ Electrical and Computer Engineering Department, is researching concepts from algebraic coding theory, cryptography, renewal/reward theory and stochastic modeling, among other areas, that will address these trade-offs in areas such as the design of error-correcting encryption systems, wireless link status and battery-power adaptive encryption. The practical aspects of her research include implementing and testing the theoretical results in battery-power constrained devices, which will have a profound effect on low-power wireless technology for secure communications.