Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

'Nano machine shop' shapes nanowires, ultrathin films

30.08.2012
A new "nano machine shop" that shapes nanowires and ultrathin films could represent a future manufacturing method for tiny structures with potentially revolutionary properties.
The structures might be tuned for applications ranging from high-speed electronics to solar cells and also may have greater strength and unusual traits such as ultrahigh magnetism and "plasmonic resonance," which could lead to improved optics, computers and electronics.

The researchers used their technique to stamp nano- and microgears; form tiny circular shapes out of a material called graphene, an ultrathin sheet of carbon that holds promise for advanced technologies; and change the shape of silver nanowires, said Gary Cheng, an associate professor of industrial engineering at Purdue University.

"We do this shaping at room temperature and atmospheric pressure, like a nano-machine shop," said Cheng, who is working with doctoral students Ji Li, Yiliang Liao, Ting-Fung Chung and Sergey Suslov and physics professor Yong P. Chen.

Graphene and nanowires – filaments 1,000 times thinner than a human hair – have numerous potential applications. However, technologies are needed to tailor them for specific uses. The new method, called laser shock-induced shaping, makes it possible to tune nanowires by altering electrical and optoelectrical properties that are critical for electronic components.

The researchers also have shown how laser shock-induced shaping can be used to change the properties of graphene, a step toward harnessing the material for electronic applications.

Findings were detailed in research papers published in the journal Nano Letters, and the work also was highlighted earlier this month in the News and Views section of the journal Nature Photonics. (The article is available at http://www.nature.com/nphoton/journal/v6/n8/full/nphoton.2012.186.html)

The technique works by using a multilayered sandwich structure that has a tiny mold at the bottom. Nanowires were situated directly above the mold, and other materials were layered between the nanowires and a glass cover sheet. Exposing this layered "forming unit" to an ultra-fast pulsing laser causes one of the layers to burn up, generating a downward pressure that forces the nanowires into the mold and changes their shape.

"The process could be scaled up for an industrial roll-to-roll manufacturing process by changing laser beam size and scanning speed," Cheng said. "The laser shock-induced shaping approach is fast and low-cost."

Part of the research, funded by the National Science Foundation, was carried out in a specialized clean room at the Birck Nanotechnology Center in Purdue's Discovery Park.

Writer: Emil Venere, 765-494-4709, venere@purdue.edu

Source: Gary J. Cheng, 765-494-5436, gjcheng@purdue.edu

Note to Journalists: Copies of the research papers are available by contacting Emil Venere, 765-494-4709, venere@purdue.edu

ABSTRACT
Nanoscale Strainability of Graphene by Laser Shock Induced 3D Shaping

Ji Li 1,2, Ting-Fung Chung 3, Yong P. Chen 1,3,4, Gary J. Cheng *1,2
1 Birck Nanotechnology Center, Purdue University
2 School of Industrial Engineering
3 School of Electrical and Computer Engineering
4 Department of Physics
Graphene has many promising physical properties. It has been discovered that local strain in a graphene sheet can alter its conducting properties and transport gaps. It is of great importance to develop scalable strain engineering techniques to control the local strains in graphene and understand the limit of the strains. Here, we present a scalable manufacturing process to generate 3-D nanostructures and thus induce local strains in the graphene sheet. This process utilizes laser induced shock pressure to generate 3-D tunable straining the graphene sheet. The size dependent straining limit of the graphene and the critical breaking pressure are both studied. It is found that the graphene film can be formed to a circular mold (~50nm in diameter) with an aspect ratio of 0.25 and strain of 12%, and the critical breaking pressure is 1.77GPa. These values were found to be decreasing with the increase of mold size. The local straining and breaking of graphene film are verified by Raman spectra. Large scale processing of the graphene sheet into nano-scale patterns is presented. The process could be scaled up to roll-to-roll process by changing laser beam size and scanning speed. The presented laser shock straining approach is a fast, tunable and low-cost technique to realize strain engineering of graphene for its applications in nano-electrical devices.

ABSTRACT

Laser Shock-Based Platform for Controllable Forming of Nanowires

Ji Li, Yiliang Liao, Sergey Suslov, and Gary J. Cheng*

Birck Nanotechnology Center and School of Industrial Engineering, Purdue University

One-dimensional nanomaterials have attracted a great deal of research interest in the past few decades due to their unique mechanical, electrical and optical properties. Changing the shape of nanowires (NWs) is both challenging and crucial to change the property and open wide functions of NWs, such as strain engineering, electronic transport, mechanical properties, band structure and quantum properties, etc. Here we report a scalable strategy to conduct cutting, bending and periodic straining of NWs by making use of laser shock pressure. Three-dimensional shaping of silver NWs is demonstrated, during which the Ag NWs exhibit very good ductility (strain-to-failure reaches 110%). Meanwhile, the high electrical conductivity of Ag NWs could retain well under controlled laser shock pressure. The microstructure observation indicates that the main deformation mechanism in Ag NWs under dynamic loading is formation of twinning and stacking fault, while dislocation motion and pile-up is less obvious. This method could be applied to semiconductor NWs as well.

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Physics and Astronomy:

nachricht Squeezing light at the nanoscale
18.06.2018 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht The Fraunhofer IAF is a »Landmark in the Land of Ideas«
15.06.2018 | Fraunhofer-Institut für Angewandte Festkörperphysik IAF

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

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

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

Im Focus: Water is not the same as water

Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.

From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Novel method for investigating pore geometry in rocks

18.06.2018 | Earth Sciences

Diamond watch components

18.06.2018 | Process Engineering

New type of photosynthesis discovered

18.06.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>