On April 13-16 at the 9th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS) in Waikiki Beach, Hawai’i,. Ferdi Hizal, PhD candidate (advisee of Prof. Chang-Hwan Choi) in the Department of Mechanical Engineering, won the Best Student Paper award for his paper titled “Nano-Engineered Alumina Surfaces for Prevention of Bacteria Adhesions.”
Bacterial adhesion poses a problem to the metals we encounter everywhere: Pipes, water-distribution systems, filtration processes, cooling facilities, ship hulls, aquaculture systems, food processing systems and bio-implants such as hips and knees. When bacteria such as E.coli and S. aureus adhere to the surface of these metals, they can lead to damage to the heart and kidneys, cause food-borne illness and a host of other serious problems.
Mr. Hizal and Prof. Choi at Stevens Institute of Technology in collaboration with the University of Hawai’i, Manoa, have found a unique solution to drastically reduce bacterial adhesion on metal surfaces. They discovered that compared to planar surfaces, a surface of nanopillars, or sharp-tipped needle-like structures (smaller than bacteria), inhibits the adhesion of the bacteria.
They also treated the surface with Teflon hydrophobic material to further discourage bacterial adhesion and growth due to the entrapped air pockets between the pillars. This further enables the bacteria to be washed off more easily with flow, minimizing bacterial infection problems and food poisoning.
“There are several different technologies or approaches to prevention of bacterial growth, killing bacteria, says Hizal. “Our approach is to simply modify the surface physically and mechanically, which shows a promising effect to avoid the bacterial adhesion without using any anti-biotic or anti-microbial drug.”
According to the corresponding author, Chang-Hwan Choi, associate professor of mechanical engineering, the nanofabrication technique that Hizal has developed for the work is unique to create nanoscale pillar structures of metals with precise control of their dimension, geometry, and wettability, uniformly over a large substrate area of arbitrary curvature. He expects that such advantages will make the application of the nanoengineered surfaces developed much practical in real applications.
“We were surprised by the results—our collaborators were also interested in new ideas about bacteria,” says Choi. “We plan to develop this idea furthermore so that we will infuse water-repelling liquids such as oil into the surface nanopatterns,”adds Choi. “We expect that such liquid-infused surfaces would be more robust to repel water and hence, prevent the bacterial adhesion on the surface. “