One Chicago skyline is dazzling enough. Now imagine 15,000 of them.
A Northwestern University research team has done just that -- drawing 15,000 identical skylines with tiny beams of light using an innovative nanofabrication technology called beam-pen lithography (BPL).
Details of the new method, which could do for nanofabrication what the desktop printer has done for printing and information transfer, will be published Aug. 1 by the journal Nature Nanotechnology.
The Northwestern technology offers a means to rapidly and inexpensively make and prototype circuits, optoelectronics and medical diagnostics and promises many other applications in the electronics, photonics and life sciences industries.
"It's all about miniaturization," said Chad A. Mirkin, George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences and director of Northwestern's International Institute for Nanotechnology. "Rapid and large-scale transfer of information drives the world. But conventional micro- and nanofabrication tools for making structures are very expensive. We are trying to change that with this new approach to photolithography and nanopatterning."
Using beam-pen lithography, the researchers patterned 15,000 replicas of the Chicago skyline (featuring the Willis Tower and the John Hancock Center) simultaneously in about half an hour. Fifteen thousand tiny pens deposit the skylines over square centimeters of space. Conventional nanopatterning technologies, such as electron-beam lithography, allow one to make similarly small structures but are inherently low throughput and do not allow one to do large-area nanofabrication.
Each skyline pattern is made up of 182 dots, with each dot approximately 500 nanometers in diameter, like each pen tip. The time of light exposure for each dot was 20 seconds. The current method allows researchers to make structures as small as 150 nanometers, but refinements of the pen architecture likely will increase resolution to below 100 nanometers. (Although not reported in the paper, the researchers have created an array of 11 million pens in an area only a few centimeters square.)
Beam-pen lithography is the third type of "pen" in Mirkin's nanofabrication arsenal. He developed polymer-pen lithography (PPL) in 2008 and Dip-Pen Nanolithography (DPN) in 1999, both of which deliver chemical materials to a surface and have since been commercialized into research-grade nanofabrication tools that are now used in 23 countries around the world.
Like PPL, beam-pen lithography uses an array of tiny pens made of a polymer to print patterns over large areas with nanoscopic through macroscopic resolution. But instead of using an "ink" of molecules, BPL draws patterns using light on a light-sensitive material.
Each pen is in the shape of a pyramid, with the point as its tip. The researchers coat the pyramids with a very thin layer of gold and then remove a tiny amount of gold from each tip. The large open tops of the pyramids (the back side of the array) are exposed to light, and the gold-plated pyramids channel the light to the tips. A fine beam of light comes from each tip, where the gold was removed, exposing the light-sensitive material at each point. This allows the researchers to print patterns with great precision and ease.
"Another advantage is that we don't have to use all the pens at once -- we can shut some off and turn on others," said Mirkin, who also is professor of medicine and professor of materials science and engineering. "Because the tops of the pyramids are on the microscale, we can control each individual tip."
Beam-pen lithography could lead to the development of a desktop printer of sorts for nanofabrication, giving individual researchers a great deal of control of their work.
"Such an instrument would allow researchers at universities and in the electronics industry around the world to rapidly prototype -- and possibly produce -- high-resolution electronic devices and systems right in the lab," Mirkin said. "They want to test their patterns immediately, not have to wait for a third-party to produce prototypes, which is what happens now."
The title of the Nature Nanotechnology paper is "Beam-pen Nanolithography." In addition to Mirkin, other authors of the paper are Fengwei Huo, Gengfeng Zheng, Xing Liao, Louise R. Giam, Jinan Chai, Xiaodong Chen and Wooyoung Shim, all from Northwestern.
Megan Fellman | EurekAlert!
Sharpening the X-ray view of the nanocosm
23.03.2018 | Changchun Institute of Optics, Fine Mechanics and Physics
Drug or duplicate?
23.03.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF
Satellites in near-Earth orbit are at risk due to the steady increase in space debris. But their mission in the areas of telecommunications, navigation or weather forecasts is essential for society. Fraunhofer FHR therefore develops radar-based systems which allow the detection, tracking and cataloging of even the smallest particles of debris. Satellite operators who have access to our data are in a better position to plan evasive maneuvers and prevent destructive collisions. From April, 25-29 2018, Fraunhofer FHR and its partners will exhibit the complementary radar systems TIRA and GESTRA as well as the latest radar techniques for space observation across three stands at the ILA Berlin.
The "traffic situation" in space is very tense: the Earth is currently being orbited not only by countless satellites but also by a large volume of space...
An international team of researchers has discovered a new anti-cancer protein. The protein, called LHPP, prevents the uncontrolled proliferation of cancer cells in the liver. The researchers led by Prof. Michael N. Hall from the Biozentrum, University of Basel, report in “Nature” that LHPP can also serve as a biomarker for the diagnosis and prognosis of liver cancer.
The incidence of liver cancer, also known as hepatocellular carcinoma, is steadily increasing. In the last twenty years, the number of cases has almost doubled...
In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.
Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.
They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
23.03.2018 | Event News
19.03.2018 | Event News
16.03.2018 | Event News
23.03.2018 | Materials Sciences
23.03.2018 | Agricultural and Forestry Science
23.03.2018 | Physics and Astronomy