— Biocompatible graphene transistor array reads cellular signals — Researchers have demonstrated, for the first time, a graphene-based transistor array that is compatible with living biological cells and capable of recording the electrical signals…
— Researchers find some smartphone models more vulnerable to attack — New research from North Carolina State University shows that some smartphones specifically designed to support the Android mobile platform have incorporated additional features that…
— MIT: New algorithm may improve defensive driving — In 2008, according to the National Highway Traffic Safety Administration, 2.3 million automobile crashes occurred at intersections across the United States, resulting in some 7,000…
— Researchers use CT to recreate Stradivarius violin — Using computed tomography (CT) imaging and advanced manufacturing techniques, a team of experts has created a reproduction of a 1704 Stradivarius violin. Three-dimensional images of…
— Terminator-style info-vision takes step towards reality — The streaming of real-time information across your field of vision is a step closer to reality with the development of a prototype contact lens that could potentially provide the wearer…
— Scientists invent long-lasting, near infrared-emitting material — Materials that emit visible light after being exposed to sunlight are commonplace and can be found in everything from emergency signage to glow-in-the-dark stickers. But until now,…
— Team of researchers develop world's lightest material — A team of researchers from UC Irvine, HRL Laboratories and the California Institute of Technology have developed the world's lightest material - with a density of 0.9 mg/cc - about…
— Humans can control a cursor with power of thought — The act of mind reading is something usually reserved for science-fiction movies but researchers in America have used a technique, usually associated with identifying epilepsy, for…
— Nanoparticles improve solar collection efficiency — Using minute graphite particles 1000 times smaller than the width of a human hair, mechanical engineers at Arizona State University hope to boost the efficiency - and profitability…
New nanocrystalline diamond probes overcome wear
Researchers at the McCormick School of Engineering and Applied Science at Northwestern University have developed, characterised, and modelled a new kind of probe used in atomic force microscopy (AFM), which images, measures, and manipulates matter at the nanoscale.
Using diamond, researchers made a much more durable probe than the commercially available silicon nitride probes, which are typically used in AFM to gather information from a material, but can wear down after several uses.
Horacio Espinosa, James and Nancy Farley Professor of Manufacturing and Entrepreneurship, and his graduate student Ravi Agrawal have shown that diamond atomic force microscopy probes are 10 times more durable than silicon nitride probes.
Their results were recently published in the Journal of Applied Physics.
'It is well-known that diamond should perform much better than other probe materials,' says Espinosa. 'However, rigourous quantification of wear and the development of models with predictive capabilities have remained elusive. It was exciting to discover that diamond probes are an order of magnitude more wear resistant than silicon nitride probes and that a single model can predict wear for both materials.'
In the study, wear tests were performed using AFM probes made from different materials - silicon nitride, ultrananocrystalline diamond (UNCD) and nitrogen-doped UNCD - by scanning them across a hard UNCD substrate. Argonne National Laboratory, where UNCD was originally invented, also supported this work by providing nitrogen-doped UNCD. Probes were made in house and also provided by Advanced Diamond Technologies, Inc. (ADT).
'It took quite an effort to develop UNCD into a sharp tip. We needed to optimise the initial stages of diamond growth to form nanometre structures with consistent results. It is really nice to find that this work paid off to demonstrate that UNCD probes are quite wear resistant, which we predicted,' said Nicolaie Moldovan, a former research professor at Northwestern University involved in the fabrication of the UNCD probes. Moldovan is now a microfabrication expert at Advanced Diamond Technologies, Inc.
In addition to characterising the probe, researchers also created a model that can predict how a probe tip will wear.
'The development of a general model with predictive capabilities is a major milestone. This effort also provided insight into how the interfacial adhesion between the probe and substrate relates to the wear resistance of AFM probes,' says Agrawal.
Neil Kane, president of ADT, said, 'The results reported in this investigation are impressive in showing the improvement in wear resistance of diamond probes. This work in part inspired the development of our commercially available NaDiaProbes(R).'
Or subscribe for our Newsletter, a free e-mail publication. It is published practically every day.
Researchers aim to mitigate impact of unintended hydrogen leaks
Nanowires will boost solar cell efficiency
Researcher invents alternative to silicon chip
Novel gas sensors for monitoring carbon dioxide