Ever stop to consider why lotus plant leaves always look clean? The hydrophobic -- water repelling -- characteristic of the leaf, termed the "Lotus effect," helps the plant survive in muddy swamps, repelling dirt and producing beautiful flowers.
Of late, engineers have been paying more and more attention to nature's efficiencies, such as the Lotus effect, and studying its behavior in order to make advances in technology. As one example, learning more about swarming schools of fish is aiding in the development of unmanned underwater vehicles. Other researchers are observing the extraordinary navigational abilities of bats that might lead to new ways to reconfigure aviation highways in the skies.
Photo courtesy of the Department of Energy.
Ranga Pitchumani, professor of mechanical engineering at Virginia Tech and currently on an invitational assignment as the chief scientist and director of the Concentrating Solar Power and Systems Integration programs of the U.S. Department of Energy's SunShot Initiative, would like to see more efficiencies and clever designs in technology. His work reflects this philosophy.
His recent development of a type of coating for materials that has little to no affinity for water emulates the Lotus effect. Commonplace material coatings are as simple as paints and varnishes. More sophisticated coatings might be used for resistance to corrosion, fire, or explosives.
The American Chemical Society recognized the impact of the work of Pitchumani and Atieh Haghdoost of Tehran, Iran, a recent doctoral graduate from Pitchumani's Advanced Materials and Technologies Laboratory, featuring their research on the cover of its April 15 issue of the publication Langmuir, a highly-cited, peer reviewed journal. The article includes a video demonstration of the coating.
Using a two-step technique, "We produced a low-cost and simple approach for coating metallic surfaces with an enduring superhydrophobic (strong water repellant) film of copper," Pitchumani explained. Copper allows for high heat and electrical conductivity, and is the material of choice in many engineering applications such as heat exchangers and electronic circuit boards.
Numerous methods currently exist to produce coating surfaces that for all practical purposes do not get wet as the water droplets run off the material. A few examples are: spraying; self-assembly where molecules spontaneously organize themselves into a structure; and laser etching.
But Pitchumani and Haghdoost explained their method "differs in that their two-step process is used to directly make superhydrophobic copper coatings without the more costly need for an additional layer of a low surface energy material."
The two-step process uses a common coating technique called electrodeposition. Again, they have a distinction -- the difference from previous manufacturing practices is that Pitchumani and Haghdoost do not use a template that can adversely affect the texture of the coating that is deposited on the surface of the material or substrate. Their template-free process allows the coating material to be made of the same material as the substrate, thereby preserving its thermal and electrical properties.
The possibilities for the technology are huge. The coatings can minimize or eliminate "fouling" -- dirt and grime accumulation -- in heat exchangers, reduce pressure drop in flow through tubes, provide improved corrosion resistance, and mitigate creep failure in electronic printed circuit board applications. They currently have an international patent pending (PCT/US2014/016312), that was filed through the Virginia Tech Intellectual Property office.
In the future, they hope to expand the nature-inspired innovation to materials other than copper.
The College of Engineering at Virginia Tech is internationally recognized for its excellence in 14 engineering disciplines and computer science. The college's 6,000 undergraduates benefit from an innovative curriculum that provides a "hands-on, minds-on" approach to engineering education, complementing classroom instruction with two unique design-and-build facilities and a strong Cooperative Education Program. With more than 50 research centers and numerous laboratories, the college offers its 2,000 graduate students opportunities in advanced fields of study such as biomedical engineering, state-of-the-art microelectronics, and nanotechnology. Virginia Tech, the most comprehensive university in Virginia, is dedicated to quality, innovation, and results to the commonwealth, the nation, and the world.
Director, News & External Relations
Lynn A Nystrom | VT News
The route to high temperature superconductivity goes through the flat land
23.11.2015 | Aalto University
Quantum spin could create unstoppable, one-dimensional electron waves
19.11.2015 | DOE/Brookhaven National Laboratory
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
AWI researchers’ unique 15-year observation series reveals how sensitive marine ecosystems in polar regions are to change
The warming of arctic waters in the wake of climate change is likely to produce radical changes in the marine habitats of the High North. This is indicated by...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
25.11.2015 | Agricultural and Forestry Science
25.11.2015 | Earth Sciences
25.11.2015 | Physics and Astronomy