Researchers from the University of Illinois at Urbana-Champaign have developed a one-step, facile method to pattern graphene by using stencil mask and oxygen plasma reactive-ion etching, and subsequent polymer-free direct transfer to flexible substrates.
Graphene, a two-dimensional carbon allotrope, has received immense scientific and technological interest. Combining exceptional mechanical properties, superior carrier mobility, high thermal conductivity, hydrophobicity, and potentially low manufacturing cost, graphene provides a superior base material for next generation bioelectrical, electromechanical, optoelectronic, and thermal management applications.
a) This is a schematic illustration of the one-step polymer-free approach to fabricate patterned graphene on a flexible substrate. A stencil mask is designed by computer-aided design software and fabricated by a laser cutter. The fabricated mask is aligned on the as-grown CVD graphene on a Cu foil, and the exposed graphene region is removed by oxygen plasma. The patterned graphene is laminated onto a flexible substrate, followed by etching of the copper foil. b) Optical microscope images and photographs of various stencil masks with sophisticated micro-scale features (top row) and corresponding graphene array patterns transferred onto SiO2 substrate and flexible Kapton film (bottom row). All scale bars: 300 μm.
Credit: University of Illinois
"Significant progress has been made in the direct synthesis of large-area, uniform, high quality graphene films using chemical vapor deposition (CVD) with various precursors and catalyst substrates," explained SungWoo Nam, an assistant professor of mechanical science and engineering at Illinois.
"However, to date, the infrastructure requirements on post-synthesis processing--patterning and transfer--for creating interconnects, transistor channels, or device terminals have slowed the implementation of graphene in a wider range of applications."
"In conjunction with the recent evolution of additive and subtractive manufacturing techniques such as 3D printing and computer numerical control milling, we developed a simple and scalable graphene patterning technique using a stencil mask fabricated via a laser cutter," stated Keong Yong, a graduate student and first author of the paper, "Rapid Stencil Mask Fabrication Enabled One-Step Polymer-Free Graphene Patterning and Direct Transfer for Flexible Graphene Devices appearing in Scientific Reports.
"Our approach to patterning graphene is based on a shadow mask technique that has been employed for contact metal deposition," Yong added. "Not only are these stencil masks easily and rapidly manufactured for iterative rapid prototyping, they are also reusable, enabling cost-effective pattern replication. And since our approach involves neither a polymeric transfer layer nor organic solvents, we are able to obtain contamination-free graphene patterns directly on various flexible substrates."
Nam stated that this approach demonstrates a new possibility to overcome limitations imposed by existing post-synthesis processes to achieve graphene micro-patterning. Yong envisions this facile approach to graphene patterning sets forth transformative changes in "do It yourself" (DIY) graphene-based device development for broad applications including flexible circuits/devices and wearable electronics.
"This method allows rapid design iterations and pattern replications, and the polymer-free patterning technique promotes graphene of cleaner quality than other fabrication techniques," Nam said. "We have shown that graphene can be patterned into varying geometrical shapes and sizes, and we have explored various substrates for the direct transfer of the patterned graphene."
In addition to Nam and Yong, study co-authors include Ali Ashraf and Pilgyu Kang from the Department of Mechanical Science and Engineering at Illinois.
SungWoo Nam | EurekAlert!
Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern
20.07.2018 | Princeton University
Relax, just break it
20.07.2018 | DOE/Argonne National Laboratory
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences