Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Using New Materials To Make More Reliable Nanoelectromechanical Systems

07.12.2010
Given their outstanding mechanical and electrical properties, carbon nanotubes are attractive building blocks for next-generation nanoelectromechanical devices, including high-performance sensors, logic devices, and memory elements. However, manufacturing challenges associated with creating well-ordered arrays of individual carbon nanotubes and the nanotube-devices’ prevalent failure modes have prevented any large-scale commercial use.

Now, researchers at Northwestern University, the Center for Integrated Nanotechnologies at Sandia and Los Alamos National Laboratories, and Binghamton University have found a way to dramatically improve the reliability of carbon nanotube-based nanoelectromechanical systems. Their results are published in the journal Small.

“Depending on their geometry, these devices have a tendency to stick shut, burn or fracture after only a few cycles,” said Horacio Espinosa, James N. and Nancy J. Professor in the McCormick School of Engineering at Northwestern University. “This significantly limits any practical application of such nano devices. Our discovery may be a key to advancing carbon nanotube-based nanoelectromechanical systems from laboratory-scale demonstrations to viable and attractive alternatives to many of our current microelectronic devices.”

To date, carbon nanotube-based nanoelectromechanical devices have ubiquitously used metal, thin-film electrodes. The Northwestern University group in collaboration with SANDIA investigators replaced these electrodes with electrodes made from diamond-like carbon (an electrically-conductive and mechanical robust material), which suppressed the onset of failure. This enabled them to demonstrate the first example of nanoelectromechanical devices constructed from individual CNTs switching reliably over numerous cycles and apply this functionality to memory elements that store binary states.

“This represents a significant step in the maturation of carbon nanotube-based device technology,” Espinosa said.

The team used a carbon nanotube-based nanoelectromechanical switch as a platform to study failure modes and investigate potential solutions.

“This switch shares operating principles, and thus failure modes, with numerous reported devices,” said Owen Loh, a graduate student in Espinosa’s lab. “In this way, we hope the results will be broadly applicable.”

First, the team conducted a parametric study of the design space of devices using conventional metal electrodes. This enabled identification of the point of onset of the various failure modes within the design space and highlighted the highly limited region in which the devices would function reliably without failure. They then used computational models to explain the underlying mechanisms for the experimentally-observed modes of failure.

“Using these models, we can replicate the geometry of the devices tested and ultimately explain why they fail,” said Xiaoding Wei, a post-doctoral fellow in Espinosa’s lab.

The team then demonstrated that using alternative electrode materials like diamond-like carbon could greatly improve the reliability of these devices. They repeated a similar parametric study using diamond-like carbon electrodes rather than metal thin films and found a dramatic improvement in device robustness. This enabled reliable switching of the carbon nanotube-based devices through numerous cycles, as well as application to the volatile storage of binary “0” and “1” states.

Other co-authors of the paper include Changhong Ke and John Sullivan.

This work was supported by the Army Research Office and National Science Foundation, and was performed in part at the Center for Integrated Nanotechnologies, a U.S. Department of Energy facility at Los Alamos National laboratory and Sandia National Laboratories, and in part at the Center for Nanoscale Materials.

Kyle Delaney | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Materials Sciences:

nachricht New value added to the ICSD (Inorganic Crystal Structure Database)
27.03.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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

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

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>