To describe the process that led his graduate student Jin-Ping Han to create an invention which just earned her a national science award, Professor Tso-Ping Ma uses the creation of "Post-Its" as an analogy. Years ago researchers at 3-M were trying to concoct the stickiest glue they could, but came up short. Somebody had the good sense, however, to figure out a use for the half-sticky glue the scientists did create. The result was the ever-popular and ubiquitous "Post-Its."
Han's prize-winning invention is a similar case of a "failure-turned-success," says Ma, professor of electrical engineering and applied physics. Han, a graduate student in electrical engineering, had been working for more than a year on a project to create a semiconductor memory device that would store data for more than 10 years in a computer's hardware. Utterly disappointed when her device had a much shorter memory, Han, with the encouragement of Ma, tried to think of some use for all the work she had put into her project. Ultimately, she used the results of this work to invent a new kind of Dynamic Random Access Memory (DRAM) cell that has the potential to introduce profound changes in both the computer and telecommunications industries.
For her invention, Han recently was selected as one of three winners in the "All-Collegiate Category" of the 1998 BFGoodrich National Collegiate Inventors Program competition. The award carries a $7,500 cash prize for Han and a $2,500 prize for Ma for his role as her adviser.
Han was among 115 students from 52 colleges and universities across the nation who submitted 83 entries for the BFGoodrich "All-Collegiate" award. Their entries were judged by a panel of eight national leaders in the fields of science, mathematics, computer science or medicine. Han and the other award winners were recognized Sept. 18 at the "Induction Weekend" for the National Inventors Hall of Fame in Akron, Ohio.
"Winning this award has been a real turning point for me," says Han, a native of China who came to Yale in 1995 as a visiting fellow and began graduate studies in electrical engineering last year. "I had really been struggling for a long time with my English, my studies and my research. This award has improved my confidence."
The DRAM cell that Han developed offers more efficient use of cell space, faster operating speed, longer data retention and lower power consumption than conventional DRAM cells. Her version of DRAM -- an essential part in computers which saves data in memory chips -- is also easier to fabricate because it has a simpler structure. Unlike conventional DRAM, which has at least one transistor and one capacitor (the actual storage unit) in each cell, Han's invention uses only one transistor per cell and eliminates the costly and large storage capacitor by storing data in the enhanced capacitance of the transitor itself. She and Ma have applied through Yale for a patent on her invention.
"Her invention will change future generations of memory because you can pack more on," says Ma. "Once commercialized, when semiconductor companies hear about this, I think they will jump ship and start using this process."
Han credits Ma for not allowing her to give up after her initial project was unsuccessful. "Rather than developing a computer memory device with at least a10-year retention time, the device I worked so long and hard on had only a 10-minute retention time," says Han. "I was extremely frustrated and disappointed. But Professor Ma encouraged me to think positively; he was the one who suggested that I try to discover whether there was something useful that could come out of the failed project."
After spending a couple of days reconsidering her project from different angles, Han came up with her new idea and went to Ma's office with her plan. "He had been having similar thoughts to my own and said it might be a great idea," comments the graduate student.
Of Han and the other student award winners, BF Goodrich chair and chief executive officer said, "The creative thinking and can-do attitudes of these students are an inspiration. They should encourage all of us to explore the wonders of science and technology."
Han plans to pass along her award money to her parents to help them buy a home in China. "I am grateful for my parents, who brought me up even through some hard times," she says. "I am also thankful to the United States, for allowing me the opportunity to study here, and to Yale, for providing such a great learning environment. And, of course, to my colleagues, for being there when I needed support."
The BF Goodrich Award is sponsored by the BF Goodrich Company, a leading provider of aircraft systems and services and a manufacturer of performance materials, and is administered by Inventure Place, home of the National Inventors Hall of Fame. This is the third time a Yale student has won the award, making the University the top scorer in BF Goodrich Collegiate Inventors Program competitions. This is also the second time Ma has been the adviser for a Yale award-winner; he also was part of the winning team in 1993 and is the only person to have advised more than one BF Goodrich award-winner. Two years ago, Professor Peter Kindlmann, also of the electrical engineering department, advised the Yale student winner of the award.