Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

An Engineered Directional Nanofilm Mimics Nature’s Curious Feats

25.10.2010
In nature, textured surfaces provide some plants the ability to trap insects and pollen, certain insects the ability to walk on water, and the gecko the ability to climb walls.

Being able to mimic these features at a larger scale would spur new advances in renewable energy and medicine. In a paper published in the October 10 issue of Nature Materials, a team of researchers from Penn State, the Naval Research Laboratory, and Harvard Medical School report on the development of an engineered thin film that mimics the natural abilities of water striding insects to walk on the surface of water, and for butterflies to shed water from their wings.

Although superhydrophobic self-cleaning surfaces are an active area of research, this development marks an engineering breakthrough in the ability to control the directionality of liquid transport. Using an array of poly(p-xylylene) nanorods synthesized by a bottom-up vapor-phase technique, the researchers were able to pin water droplets in one direction with enormous adhesive forces proportional to the number of nanorods and the surface tension, while releasing droplets in the opposite direction.

The differential between the pin and release force is 80 micronewtons, over ten times the values reported in other engineered surfaces with ratchet-like features, and the first such surface to be engineered at the nanoscale. Recently, the authors also demonstrated directional adhesion and friction of these surfaces, similar to the way a gecko can climb a wall (J. Applied Physics, 2010). Gecko’s feet contain approximately 4 million hairs per square millimeter, whereas polymer nanorods can be deposited at 40 million rods per square millimeter.

The nanofilm produced by this technique, called oblique angle deposition, provides a microscale smooth surface for the transport of small water droplets without pumps or optical waves and with minimal deformation for self-powered microfluidic devices for medicine and for microassembly.

In work sponsored by the U.S. Navy, the nanofilm is envisioned for use as a coating that would reduce drag on the hull of vessels and retard fouling. Potential industrial and energy related uses are as directional syringes and fluid diodes, pump-free digital fluidic devices, increased efficiency of thermal cooling for microchips, coatings for tires, and even in energy production from rain drops.

The lead on the Penn State team, Melik Demirel, associate professor of engineering science and mechanics and corresponding author on the report, believes that the current laboratory based vapor phase technique, which although relatively simple still requires a vacuum, can be replaced by a liquid phase technique, which would allow for scaling the production of their material to industry size. “The major impact of our method is that for the first time we can create a controlled directional surface at the nanoscale,” Demirel concludes.

Funding for the Penn State research comes from the Office of Naval Research through a Young Investigators Grant to Demirel. Other authors include Niranjan Malvadkar, former Ph.D. student in Demirel’s lab and now a scientist at Dow Chemical R&D, and Koray Sekeroglu, a current Ph.D. student in Demirel’s lab, Matthew Hancock from Brigham and Women’s Hospital, Harvard Medical School, and Walter Dressick from the Naval Research Laboratory. The paper, “An engineered anisotropic nanofilm with unidirectional wetting properties,” is available at http://www.nature.com/nmat/journal/vaop/ncurrent/abs/nmat2864.html.

Contact Prof. Melik C. Demirel, Ph.D., at mdemirel@engr.psu.edu or 814-863-2270.

Prof. Melik C. Demirel | Newswise Science News
Further information:
http://www.psu.edu

Further reports about: Demirel Laboratory Medical Wellness Melik Mimics Nanofilm Naval microfluidic device water droplets

More articles from Materials Sciences:

nachricht Argon is not the 'dope' for metallic hydrogen
24.03.2017 | Carnegie Institution for Science

nachricht Researchers make flexible glass for tiny medical devices
24.03.2017 | Brigham Young University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>