Posts tagged technology
UNEXPECTED ADHESION PROPERTIES OF GRAPHENE MAY LEAD TO NEW NANOTECHNOLOGY DEVICES
Aug 23rd
The new findings — that graphene has surprisingly powerful adhesion qualities — are expected to help guide the development of graphene manufacturing and of graphene-based mechanical devices such as resonators and gas separation membranes, according to the CU-Boulder team. The experimentsshowed that the extreme flexibility of graphene allows it to conform to the topography of even the smoothest substrates.
Graphene consists of a single layer of carbon atoms chemically bonded in a hexagonal chicken wire lattice. Its unique atomic structure could some day replace silicon as the basis of electronic devices and integrated circuits because of its remarkable electrical, mechanical and thermal properties, said Assistant Professor Scott Bunch of the CU-Boulder mechanical engineering department and lead study author.
A paper on the subject was published online in the Aug. 14 issue of Nature Nanotechnology. Co-authors on the study included CU-Boulder graduate students Steven Koenig and NarasimhaBoddeti and Professor Martin Dunn of the mechanical engineering department.
“The real excitement for me is the possibility of creating new applications that exploit the remarkable flexibility and adhesive characteristics of graphene and devising unique experiments that can teach us more about the nanoscale properties of this amazing material,” Bunch said.
Not only does graphene have the highest electrical and thermal conductivity among all materials known, but this “wonder material” has been shown to be the thinnest, stiffest and strongest material in the world, as well as being impermeable to all standard gases. It’s newly discovered adhesion properties can now be added to the list of the material’s seemingly contradictory qualities, said Bunch.
The CU-Boulder team measured the adhesion energy of graphene sheets, ranging from one to five atomic layers, with a glass substrate, using a pressurized “blister test” to quantify the adhesion between graphene and glass plates.
Adhesion energy describes how “sticky” two things are when placed together. Scotch tape is one example of a material with high adhesion; the gecko lizard, which seemingly defies gravity by scaling up vertical walls using adhesion between its feet and the wall, is another. Adhesion also canplay a detrimental role, as in suspended micromechanical structures where adhesion can cause device failure or prolong the development of a technology, said Bunch.
The CU research, the first direct experimental measurements of the adhesion of graphene nanostructures, showed that so-called “van der Waals forces” — the sum of the attractive or repulsive forces between molecules — clamp the graphene samples to the substrates and also hold together the individual graphene sheets in multilayer samples.
The researchers found the adhesion energies between graphene and the glass substrate were several orders of magnitude larger than adhesion energies in typical micromechanical structures, an interaction they described as more liquid-like than solid-like, said Bunch.
The CU-Boulder study was funded primarily by the National Science Foundation and the Defense Advanced Research Projects Agency.
The importance of graphene in the scientific world was illustrated by the 2010 Nobel Prize in physics that honored two scientists at Manchester University in England, Andre K. Geim and Konstantin Novoselov, for producing, isolating, identifying and characterizing graphene.
There is interest in exploiting graphene’s incredible mechanical properties to create ultrathin membranes for energy-efficient separations such as those needed for natural gas processing or water purification, while graphene’s superior electrical properties promise to revolutionize the microelectronics industry, said Bunch.
In all of these applications, including any large-scale graphene manufacturing, the interaction that graphene has with a surface is of critical importance and a scientific understanding will help push the technology forward, he said.
Online advertising does not work?? Oh no kidding by Jann Scott
Jul 15th
First of all it costs too much money according to Trada ceo. Then SM kid Gabe Lee spread an article around face book saying Banner ads are a loser. Now these are two people who are speaking out of school in the ad world??
yep, But we agree with them.
HERE’S THE RUB: We’ve in in the advertising business at the local level for 30 years so we know what get results for advertisers. We have to or we would not be in business. Advertisers want results. They want to see income levels go up as a result of buying advertising.
You’ll notice Banner ads on the right side here. Do they work?? Yep. Why. Because we treat our advertisers as kings and queens. We don’t treat them as marks the way most online companies do. LIKE FACEBOOK, TWITTER and most of the Boulder online ad houses. What do I mean by that.??
We give our advertisers a full service compliment, track every hit, and we provide them with everything from video to pr. We don’t just sell them. We make it happen for them. We work their business for them. Ask them. They love us. If you are local and you want inexpensive old school results in a world of new technology call me Jann Scott 303 447 8531
CU STUDENT INSTALLATIONS TO HELP ENGAGE COMMUNITY IN UNIVERSITY HILL DEVELOPMENT
Jun 1st
The temporary installations will serve as the basis of a community charrette, an intense planning and design collaboration, from 8:30 to 11:30 a.m. on June 3. The event is part of the International Town & Gown Association conference and is cosponsored by the city of Boulder.
“We take great pride in partnering with the city to provide opportunities for students to solve real-world problems,” said Frank Bruno, vice chancellor for administration. “The ability of our students to connect and engage the University Hill community through this interdisciplinary project is truly remarkable and can result in progress for the neighborhood.”
Charrette participants will explore revitalization ideas for University Hill that encompass the education, research and community service resources of CU-Boulder and the vibrant culture of the area as a commercial and residential district, according to organizers.
The project stems from a CU-Boulder Maymester course called Finding Ground. The student works include two interactive survey boards, two tables and 25 hammocks, all for public use.
“The installations are meant to bring people together to explore ideas for community connectedness and the overall use of public space,” said Finding Ground student Richard Mapes, a senior in architecture. “It’s amazing to see so many groups working to positively change the course of University Hill.”
Students carried out mapping exercises, interviews, precedent studies and presentations. They also conceptualized, designed and built the installations.
“We are excited about the close collaboration we’ve had with the university in preparing for this event, and look forward to learning more about the students’ work and their creative ideas during Friday’s charrette,” said David Driskell, executive director of Community Planning and Sustainability for the city of Boulder. “University Hill is a unique Boulder neighborhood, where the university and community literally come together. This course and Friday’s activities are just one example of how we can work together to make the Hill a vibrant and successful place that is welcoming for everybody.”
Students also maintained a group blog and developed a quick response code, which is displayed on three project information signs located on University Hill. It also will be stenciled in chalk on University Hill sidewalks. Visitors with the appropriate cellular phone technology can scan the QR code to be linked to the project website for more information.
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