Hub of the Air Universe

As the world celebrates a century of flight, most people have been looking back to the events in Kitty Hawk, NC. However, a new MIT Museum exhibit, Hub of the Air Universe: A Century of Flight in Massachusetts, highlights important aeronautical advances that came out of the Bay State, including the development of radar, the jet engine, and the Apollo spacecraft navigation system.

The exhibit features several artifacts, including six and a half square centimeters of the original fabric that covered the Wright brothers’ Flyer 1, and the frame of Chrysalis, a human-powered airplane built by MIT students and alumni. But most of the exhibit is a wealth of historic news articles and photos from the State Street Bank Collection, created by the bank’s former vice president of public affairs, Ralph Eastman. Since Eastman’s collection isn’t very systematic, curator Deborah Douglas borrowed its haphazard tone when designing the exhibition. “I wanted to recreate that sketchbook feeling,” she says.

Of all the MIT alumni featured in the exhibit, perhaps Jerome Hunsaker, SM ‘12, SCD ‘23, is the most notable. In 1914, he taught MIT’s-and the country’s-first aviation design course and built the nation’s first modern wind tunnel. He also designed the Curtiss NC-4, the first airplane to cross the Atlantic. The exhibition runs until September 5.

Into Africa

This summer, an interdisciplinary group of some 15 MIT undergraduate and graduate students will travel to universities and high schools in Ghana, Ethiopia, and Kenya to lead Internet technology education programs. This year marks the fifth anniversary of the MIT African Internet Technology Initiative, a student-run program Kenyan Paul Njoroge ‘00, Mng ‘02, dreamed up to send MIT students to his home country to teach computer programming skills to local students and teachers.

The MIT volunteers teach African students to program in Java and use a variety of open-source technologies, including the Linux operating system. The initiative also hopes to encourage the African students to make use of their new skills in local businesses.

MIT students learn as much from the experience as the African students, according to cofounder and current president Solomon Assefa ‘01, Mng ‘01, an Ethiopian electrical engineering and computer science doctoral candidate. “They come back with a whole new perspective on life, refreshed with the vastly unique cultural experience,” he says.

The program, which pays for MIT students’ flights, accommodations, and living expenses, has received funding from former MIT president Paul Gray ‘54, SM ‘55, ScD ‘60, many MIT offices, and several companies and nonprofit organizations.

Fine Liner

Researchers at MIT’s Space Nanotechnology Laboratory have built a device called the Nanoruler that can, in only 20 minutes, write parallel lines just a few hundred nanometers apart on a pizza-sized silicon wafer. Until now, inscribing such wafers has been a challenge, because the larger the surface, the greater the chance for error. But according to lab director Mark Schattenburg, PhD ‘84, the Nanoruler-which he invented-is up to a thousand times faster and more precise than previous methods and could usher in a cheaper, more accurate way to produce components that are used in telescopes or serve as guides for the manufacture of semiconductor chips.

Manufacturers have previously relied on either mechanical ruling or interference lithography to inscribe lines-known as “gratings”-on silicon. Mechanical ruling, a process that can take weeks, uses a diamond-tipped tool to etch each line. Interference lithography uses laser beams to create an interference pattern of lines that is captured by light-sensitive material on the wafer. Though fast, this technique is vulnerable to error when larger wafers are used: the larger the interference pattern, the greater the chance that atmospheric changes will alter the laser’s wavelength and cause the lines to distort.

The Nanoruler is less susceptible to error because its interference pattern is only a millimeter in diameter. The tiny pattern is projected on a wafer that sits on a movable stage, which moves back and forth under the laser, until the wafer is covered with precisely spaced lines.

A task for the new tool might be to help fabricate 100 square meters’ worth of gratings for Constellation-X, a set of NASA x-ray telescopes currently under development.

Dance Machine

As a championship swing dancer, Sommer Gentry knows that when her dance partner leads, he does so with touch cues, not words. Gentry, a graduate student in MIT’s Department of Electrical Engineering and Computer Science, conducted experiments to test whether this kind of touch-based communication could be applied to human interactions with robots and recently won an IEEE award for her work. Her findings could prove useful in, among other things, robotic-surgery applications.

Gentry programmed a commercial desktop robotic arm to move in four sequences of circles and arcs to the beat of “New York, New York.” Test subjects learned the sequences by holding the robot’s “hand,” then attempted to follow its lead as it strung the sequences together randomly. Gentry found that once the subjects recognized the moves the robot was performing, their response time fell to less than 100 milliseconds-less than the time it takes for a nerve signal to travel up the arm to the brain and for the brain to initiate a reaction. Gentry thinks this kind of communication could work well in applications such as surgery. A robotic device could be programmed, for example, to teach a medical student how to suture. The device could gently guide the student’s hands through certain motions-weaving forceps, grabbing a thread, and pulling it tight-on specific beats.

Her next experiments will involve more complicated dance patterns and might give the robot a chance to make adjustments for the follower’s errors.

Infantry Innovations

MIT’s Institute for Soldier Nanotechnologies may be harnessing nanotech to equip tomorrow’s soldiers, but some of its earliest contributions may come in the form of collapsible bolt cutters or energy-efficient flashlights with multiple colored beams. These macro-scale innovations were among the entries in the ISN’s Soldier Design Competition, which awarded prizes of $5,000, $3,000, and $2,000 to three teams in February.

The contest, which kicked off last September, had the dual goal of addressing common needs of foot soldiers and encouraging undergraduates to practice design (each team was required to include at least two undergrads). In November, nine teams’ projects were selected from among the 23 proposals received. The teams chosen were given $750 each to build working prototypes that were judged by a panel of about a dozen faculty, military, and industry representatives in February.

Team TacShot took first prize for a rocket-mounted camera that snaps photographs as it tumbles down to earth after launch, beaming the images to a computer that assembles them into an aerial panorama. Second prize went to the Surreptiles for their sensor-laden glove that translates hand signals into voice commands that are beamed to squad members’ personal radios. In third place was Team TXI, which invented a more reliable parachute releasing mechanism.

Several of the teams hope to commercialize their inventions, using this year’s MIT $50K Entrepreneurship Competition as a springboard.

Debunking the Low-Tar Myth

Since the 1960s, many smokers have been persuaded that switching from medium-tar cigarettes to low-tar cigarettes would be good for their health. However, according to a recent study by economics professor Jeffrey Harris and three American Cancer Society analysts, the risk of dying from lung cancer is the same whether smokers use very-low-tar, low-tar, or medium-tar cigarettes.

Their study, published in the British Medical Journal, compared 1982 American Cancer Society data on nearly one million subjects with data on the same participants over the next six years. Those who smoked filtered cigarettes were grouped into three categories, according to their cigarettes’ tar content. The researchers found that participants’ likelihood of dying from lung cancer was the same across the three groups.

“This finding, in my view, increases the urgency and necessity of revising the cigarette rating system,” Harris says. Cigarette manufacturers base tar ratings on the amount of tar machines accumulate from smoking cigarettes, smoking every cigarette the same way. Humans, however, take more frequent, deeper puffs from low-tar cigarettes than they do from ones with more tar, which could explain the study’s results, Harris says. In addition to teaching, Harris is a primary-care internist; he tells his patients that switching to low-tar cigarettes will not improve their health, but quitting will.