all electrical engineering stories

China could meet its energy needs by wind alone

404132862 — Thu, 10 Sep 2009 11:26:40 -0400

A team of environmental scientists from Harvard and Tsinghua University has demonstrated the enormous potential for wind-generated electricity in China. Using extensive meteorological data and incorporating the Chinese government’s energy-bidding and financial restrictions for delivering wind power, the researchers estimate that wind alone has the potential to meet the country’s electricity demands projected for 2030.

Scholar makes robots that detect land mines

50443248 — Thu, 28 May 2009 14:29:33 -0400

On Oct. 10, 2005 — he remembers the date exactly — Thrishantha Nanayakkara was driving down a country road, headed for a science workshop at Jaffna Central College, a high school in the far north of Sri Lanka. The event was designed to distract potential child soldiers from the allure of war.

His cell phone rang. It was a government official, with a tip-off. “Turn back,” the caller said, in so many words, “or you will be killed.”

Cherry A. Murray is named dean of SEAS

90581724 — Tue, 10 Mar 2009 11:56:42 -0400

Cherry A. Murray, who has led some of the nation’s most brilliant scientists and engineers at Bell Laboratories and the Lawrence Livermore National Laboratory, has been appointed dean of Harvard University’s School of Engineering and Applied Sciences (SEAS), effective July 1, 2009.

She will also become the John A. and Elizabeth S. Armstrong Professor of Engineering and Applied Sciences.

Evelyn Hu named professor of applied physics, electrical engineering in SEAS

404132862 — Tue, 04 Nov 2008 12:08:54 -0500

Evelyn L. Hu, a pioneer in the fabrication of nanoscale electronic and photonic devices, has been named Gordon McKay Professor of Applied Physics and Electrical Engineering in Harvard University’s School of Engineering and Applied Sciences (SEAS), effective Jan. 1, 2009.

Hu, 61, is currently professor of electrical and computer engineering at the Uni-versity of California, Santa Barbara (UCSB), a position she has held since 1984. She has also served since 2000 as scientific co-director of the California Nanosystems Institute, a joint initiative at UCSB and the University of California, Los Angeles.

Scientists demonstrate highly directional semiconductor lasers

404132862 — Thu, 24 Jul 2008 13:42:02 -0400

Applied scientists at Harvard collaborating with researchers at Hamamatsu Photonics in Hamamatsu City, Japan, have demonstrated, for the first time, highly directional semiconductor lasers with a much smaller beam divergence than conventional ones. The innovation opens the door to a wide range of applications in photonics and communications. Harvard University has also filed a broad patent on the invention.

Creating semiconductor lasers

404132862 — Thu, 24 Jul 2008 13:45:57 -0400

Lasers are often considered to be highly directional light sources:
their beams are able to propagate over long distances without
substantial spreading. This, however, is not always the case.
Semiconductor lasers, the most commonly used among all lasers, suffer
from a large beam divergence. Such divergence is governed by the
principle of diffraction, which predicts bending and spreading of light
around small obstacles or apertures. Light beams endure strong
diffraction when emerging from the small light-emitting regions of
semiconductor lasers (the dimensions of which are comparable to the
laser wavelength). This leads to a beam divergence angle of tens of
degrees for most semiconductor lasers.

Researchers develop new technique for fabricating nanowire circuits

404132862 — Thu, 26 Jun 2008 12:11:39 -0400

Scientists at Harvard's School of Engineering and Applied Sciences (SEAS), collaborating collaborating with researchers from the German universities of Jena, Gottingen, and Bremen, have developed a new technique for fabricating nanowire photonic and electronic integrated circuits that may one day be suitable for high-volume commercial production.

Laser advance could open up new markets

Fri, 13 Jul 2007 10:40:24 -0400

Applied scientists from Harvard University have, for the first time, demonstrated high-power continuous wave (cw) room-temperature quantum cascade (QC) lasers made by a well-established mass production semiconductor synthesis technique. The breakthrough could soon lead to the large-scale commercialization of QC lasers and open up new markets for laser-based chemical sensors.

The new generation of QC lasers relies on a layer deposition technique known as Metallorganic Vapor Phase Epitaxy (MOVPE), one of the most common and versatile methods for mass-producing technology for semiconductor lasers, circuits, and other photonics components for communications.

Solitons may be the next wave in electronic circuits

Wed, 18 Jul 2007 11:12:27 -0400

Harvard scientists have solved the puzzle of how to generate a special form of wave in small electronic devices, allowing the electrical equivalent of the pulses of light that carry signals through optical cables.

The advance, highlighted in the March 2 issue of the journal Nature, occurred in the Harvard lab of Donhee Ham, assistant professor of electrical engineering in the Division of Engineering and Applied Sciences.

The special waves, called solitons, are valuable in commercial and engineering applications because they are single, stable waves that don't lose strength as they travel large distances. Soliton waves in optical fibers, for example, have transferred large amounts of information over thousands of kilometers with no errors in the signal.

Berkman Center helps launch StopBadware campaign

70652986 — Mon, 26 Mar 2007 06:24:14 -0400

The problems caused by badware have very serious implications, both for every day use of computers, and for the long-term viability of the open Internet. On Jan. 25, 2006, the Berkman Center, the Oxford Internet Institute, Consumer Reports WebWatch, and a wide range of corporate sponsors announced the StopBadware.org initiative, a project aimed at stopping the creation of badware - a.k.a. spyware, malware, or deceptive adware.

In the short term, the goals of the project are ambitious but straightforward - create a community of anti-badware volunteers and researchers who will collaborate to create a clearinghouse of data and research on badware, and share that data with the world. The project Web site is http:// www.StopBadware.org. The project also will investigate the possibilities of creating a kind of "software stethoscope," which when installed by millions of users would give a global peak into the health of the Internet and the PCs connected to it.

Student makes cableless cable

70652986 — Mon, 26 Mar 2007 06:18:02 -0400

Matthew DePetro '05 earned top honors for his senior design project, "Wireless Cable Television." The first-prize entry "untethers" standard cable TV and even eliminates the need for a wall outlet.

"All of the rooms that I have lived in at Harvard have such crummy standard TV reception that something as simple as watching the 11 o'clock news is an unfulfilling experience," says DePetro. "Unfortunately, cable television service suffers from the inherent shackles of a cable for signal distribution. In a typical dorm residence that means television sets must be located near a cable outlet in the wall."

Moreover, setting up cable for multiple sets in separate rooms requires adding extra wiring infrastructure within a building itself - no easy feat in older structures.

A giant step toward miniaturization

70652986 — Mon, 26 Mar 2007 05:35:38 -0400

Incredibly tiny integrated circuits could have applications well beyond faster, smaller computers and cell phones with features only fantasized about today. For example, nanocircuits might make possible sensors that can detect a single virus in your blood. "It could turn manufacturing of high-end technology upside down," says Charles Lieber, Mark Hyman Jr. Professor of Chemistry. "It could affect all electronic circuits in the world. And that's really cool." This is the first time that bridging two different types of materials has been done at the nanometer level. The implications for more efficient electronics and sensing devices are obvious. Lieber is already working with Intel Corp., the world's largest producer of electronic chips.

New use found for black silicon

70652986 — Mon, 26 Mar 2007 05:15:59 -0400

In 1999, Harvard researchers used laser pulses to etch the surface of silicon, the most common substance used in electronic devices. By accident, they created a material that efficiently traps light. Called black silicon, it holds amazing potential for efficiently converting sunlight to electricity, for communicating by light, and for monitoring the environment for evidence of pollution and global warming. Now, a Harvard graduate student has discovered another use for black silicon. When placed in a strong electric field, the substance emits electrons with surprising efficiency.

Thinnest wires probe superconductivity

70652986 — Mon, 26 Mar 2007 05:03:53 -0400

Wires made by a team of Harvard University researchers are almost too small to imagine – thousands of times thinner than a human hair and just millionths of an inch long. The long-term result may be computers much smaller and faster than the speediest supercomputers available today. Such supercomputers would be super cool, operating at about minus 458 degrees Fahrenheit. How small can such machines be? That depends on how small their wires can be made and still function as superconductors. No one knew the lower limits until Harvard physicists provided the first answer: roughly 5 millionths of a millimeter across (5 nanometers), or about 200 thousandths of an inch.

Student-designed lamp brightens Harvard dorms

70652986 — Mon, 26 Mar 2007 05:11:06 -0400

Halogen lamps became increasingly popular through the '90s. Their high-wattage bulbs gave off a clear, pleasant light and -- at $15 to $25 -- even a student could afford them. Unfortunately, the lamps also gobbled electricity and their bulbs burned hot enough to be blamed for several fires and two fatalities. As part of her senior thesis, Harvard College undergraduate Linsey Marr, Class of 1996, designed an energy-saving floor lamp to replace the hot-burning halogen torchiere lamps. Now a lamp based on Marr's design is being used at Harvard and sold commercially by Energy Federation Inc., which produced a commercially viable version of the lamp.