Vol. 5 Num 1025 Fri. April 20, 2007  

Feats of a Bangladeshi scientist

Recently Dr Abul Hussam, a Bangladeshi born professor at George Mason University in Fairfax, Virginia, US, made news when he was named the winner of the million dollar Grainger Challenge awarded by the US National Academy of Engineering, for developing an inexpensive filtration system for arsenic contaminated water. This low-cost device may help put an end to what the World Health Organization call the "largest mass poisoning of a population in history."

A team of researchers led by Dr Taher Saif, a professor of Bangladeshi origin in the Mechanical Science and Engineering Department at University of Illinois at Urbana-Champaign, also made news worldwide.

The panel, headed by him and assisted by Jong Han and Jagannathan Rajagopalan, two graduate students, demonstrated that slightly modified metals remember their original shapes and bend. Dented and crumpled metal can snap back to the unbent shape and form, with a little heat.

The research was funded by the National Science Foundation, and the findings were published in the March 30, issue of the Journal of Science. The novel innovation has been publicized in news dailies all over the world, but amazingly and unfortunately, nary a pip in his native country or in the Bangladesh media. There have been features on Dr Saif and his landmark achievement in the US, China (The People's Daily), Australia, India, Malaysia and elsewhere.

Normally, if a hanger or even a paper clip is bent, it is nearly impossible to restore the metal to the 100% original state. Physical properties like this are determined by the metal's crystalline and chemical structure.

The crystalline structure, or microstructure, is the result of tiny groups of atoms that take on different sizes, depending on how the atoms within each group are packed together. When bent or dented these atoms become unyielding, and refuse to revert to the original shape.

Dr Saif and his associates have concocted metals that remember their original shapes and, with a little heating, can snap back to new after being crumpled or dented.

"We showed for the first time that metal can snap back after deformation," Dr Taher Saif told the New York based LiveScience magazine (April 2 issue).

Dr Saif graduated from Bangladesh University of Engineering & Technology (Buet) with a BS in Civil Engineering (Structure) in 1984. He joined Buet as a faculty member in 1984, and worked as a lecturer in the Civil Engineering Department for two years prior to leaving for the US to pursue higher studies in 1986.

He received a Masters in Civil Engineering from Washington State University in 1987, and a PhD. in Theoretical and Applied Mechanics from renowned Cornell University in 1993. He was a Post-Doctoral Fellow at Cornell from 1993 to 1996, and worked as a Research Associate at the same university in 1996-97.

Dr Taher Saif joined University of Illinois at Urbana, Champaign, as a faculty member in1997. He was promoted to the rank of Associate Professor in the Department of Mechanical and Industrial Engineering in 2003, and is currently serving as a Willett Faculty Scholar and a researcher at the university's Micro and Nanotechnology Laboratory.

In the study, Dr Saif and graduate students Jagannathan Rajagopalan and Jong H. Han, explored aluminum films and gold films. The aluminum films were 200 nanometers thick, 50-60 microns wide and 300-360 microns long. The gold films were 200 nanometers thick, 12-20 microns wide and 185 microns long (News Bureau, University of Illinois at Urbana Champaign, 29 March. 2007).

They found that the type of metal did not matter. What mattered was the size of the grains in the metal's crystalline microstructure, and a distribution in the size. If the grains are uniformly too small, the metal will be brittle and break while being bent.

If the grains are uniformly too large, the metal will bend, but then stay in that position. To return to the initial shape, what's needed is a balance between brittleness and malleability. That balance can be achieved through a combination of small and large grains.

Variations in the microstructure lead to plastic deformation in the larger grains and elastic accommodations in the smaller grains. The bigger grains bend, but push and pull on the smaller grains, which become elastically deformed, like a spring.

If the metal is then left alone, the smaller grains will release this energy and force the bigger grains back to their original shapes over time. Applying heat can speed up this local release of energy.

The pioneering research has widespread and far-reaching significance and practical use. Modified metals that can regain their original shape even after they have been bent may soon be available.

After a fender bender caused by a car accident, for example, the springy gains in the modified metal could get sprung and release all their stored energy and force the big grains back to their initial positions (LiveScience, April 2).

Bent bumpers that straighten overnight, dents in car doors that disappear, and bent out of shape metal structures magically regaining the original shape and look, may all become possible due to the ground-breaking research of a Bangladeshi engineer.

The author is an administrator at a private university.