all Donhee Ham stories

Five faculty members named young innovators by Technology Review

404132862 — Tue, 19 Aug 2008 12:24:12 -0400

Work on flying robots, surgical tape modeled on gecko feet, energy tips gleaned from plants, new ways to grow stem cells, and dramatically smaller medical imaging equipment has landed five Harvard faculty members on a list of the world’s top 35 young innovators.

The annual list is compiled by Technology Review magazine and features what the editors and a panel of judges see as the 35 top innovators in business and technology who are under the age of 35.

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.

Scientists create high-speed nanowire circuits

50443248 — Tue, 24 Jul 2007 15:15:22 -0400

Chemists and engineers at Harvard University have made robust circuits from minuscule nanowires that align themselves on a chip of glass during low-temperature fabrication, creating rudimentary electronic devices that offer solid performance without high-temperature production or high-priced silicon.
The researchers, led by chemist Charles M. Lieber and engineer Donhee Ham, produced circuits at low temperature by running a nanowire-laced solution over a glass substrate, followed by regular photolithography to etch the pattern of a circuit. Their merging of low-temperature fabrication and nanowires in a high-performance electronic device is described this week in the journal Nature.

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.