Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Nanotechnology: Feel the pressure

29.03.2012
Nanowires have superior electrical and mechanical properties and can be put to good use in pressure sensors
Miniaturized pressure sensors are widely used in mechanical and biomedical applications, for example, in gauging fuel pressure in cars or in monitoring blood pressure in patients. Woo-Tae Park and co-workers at the A*STAR Institute of Microelectronics1 have now developed a nanowire-based sensor that is so sensitive it can detect even very low pressure changes.

Most miniaturized pressure sensors harness the intrinsic properties of piezoresistive materials. A structural change in such a material, induced for example by an external force, results in a complementary change in its electrical resistance. However, piezoresistive materials have two major limitations. Firstly, these materials are not particularly sensitive, which means that low pressures produce weak electronic signals. Secondly, these materials can generate a lot of electrical noise, which can mask the true measurement signal. An ideal transducer should have a high signal-to-noise ratio (SNR). Park and his co-workers have now used nanowires to create a pressure sensor with enhanced SNR properties.

Previous research has shown that nanowires can exhibit high piezoresistive effects because of their small size. To take advantage of this, Park and his co-workers used state-of-the-art material processing techniques to suspend two silicon nanowires between two electrodes on a silicon-on-insulator substrate. Each wire was a few hundred nanometers long and approximately 10 nanometers wide. They were covered in amorphous silicon which both protected them and acted as an electrical connection, referred to as the gate. The researchers attached to this a circular diaphragm: a two-layer membrane of silicon nitride and silicon dioxide. Any stress in the diaphragm was therefore transferred to the nanowire structure.

The team characterized their sensor by passing a controlled stream of air across it. Ammeters measured the current flowing through the device as a known electrical potential was applied across the two electrodes. An additional voltage, the gate bias, was also applied between one of the electrodes and the gate. Park and his co-workers demonstrated that they could achieve a four-fold increase in pressure sensitivity by reversing the direction of this gate bias. This, they believe, is a result of the bias voltage controlling the confinement of the electrons within the nanowire channels — a concept commonly employed in so-called field-effect transistors. An assessment of the device noise characteristics also showed significant improvements with the right choice of operating parameters.

Park and his co-workers believe that the device provides a promising route for applications requiring miniaturized pressure sensors that use little power.

The A*STAR-affiliated researchers contributing to this research are from the Institute of Microelectronics

Lee Swee Heng | Research asia research news
Further information:
http://www.research.a-star.edu.sg
http://www.researchsea.com

More articles from Power and Electrical Engineering:

nachricht Researchers use light to remotely control curvature of plastics
23.03.2017 | North Carolina State University

nachricht TU Graz researchers show that enzyme function inhibits battery ageing
21.03.2017 | Technische Universität Graz

All articles from Power and Electrical Engineering >>>

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

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>