Virginia Tech mechanical engineer develops new low-cost material coating technique
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.
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 www.solar.energy.gov, 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, a recent doctoral graduate from Pitchumani’s Advanced Materials and Technologies Laboratory (www.me.vt.edu/amtl), featuring their research on the cover of its April 15 issue of the publication Langmuir, a highly-cited, peer reviewed journal. The article can be found at: http://pubs.acs.org/doi/abs/10.1021/la403509d, which 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.
Lynn Nystrom | newswise
Fraunhofer researchers develop measuring system for ZF factory in Saarbrücken
21.11.2017 | Fraunhofer-Institut für Zerstörungsfreie Prüfverfahren IZFP
New manufacturing process for SiC power devices opens market to more competition
14.09.2017 | North Carolina State University
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...
Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.
To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...
The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.
Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...
With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong
Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...
11.12.2017 | Event News
08.12.2017 | Event News
07.12.2017 | Event News
14.12.2017 | Health and Medicine
14.12.2017 | Physics and Astronomy
14.12.2017 | Life Sciences