Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Tiny levers, big moves in piezoelectric sensors

24.11.2011
A team of university researchers, aided by scientists at the National Institute of Standards and Technology (NIST), have succeeded in integrating a new, highly efficient piezoelectric material into a silicon microelectromechanical system (MEMS).* This development could lead to significant advances in sensing, imaging and energy harvesting.

A piezoelectric material, such as quartz, expands slightly when fed electricity and, conversely, generates an electric charge when squeezed. Quartz watches take advantage of this property to keep time: electricity from the watch's battery causes a piece of quartz to expand and contract inside a small chamber at a specific frequency that circuitry in the watch translates into time.

Piezoelectric materials are also in sensors in sonar and ultrasound systems, which use the same principle in reverse to translate sound waves into images of, among other things, fetuses in utero and fish under the water.

Although conventional piezoelectric materials work fairly well for many applications, researchers have long sought to find or invent new ones that expand more and more forcefully and produce stronger electrical signals. More reactive materials would make for better sensors and could enable new technologies such as "energy harvesting," which would transform the energy of walking and other mechanical motions into electrical power.

Enter a material named PMN-PT.**

A large team led by scientists from the University of Wisconsin-Madison developed a way to incorporate PMN-PT into tiny, diving-board like cantilevers on a silicon base, a typical material for MEMS construction, and demonstrated that PMN-PT could deliver two to four times more movement with stronger force -- while using only 3 volts -- than most rival materials studied to date. It also generates a similarly strong electric charge when compressed, which is good news for those in the sensing and energy harvesting businesses.

To confirm that the experimental observations were due to the piezoelectric's performance, NIST researcher Vladimir Aksyuk developed engineering models of the cantilevers to estimate how much they would bend and at what voltage. Aksyuk also made other performance measures in comparison to silicon systems that achieve similar effects using electrostatic attraction.

"Silicon is good for these systems, but it is passive and can only move if heated or using electrostatics, which requires high voltage or large dissipated power," says Aksyuk. "Our work shows definitively that the addition of PMN-PT to MEMS designed for sensing or as energy harvesters will provide a tremendous boost to their sensitivity and efficiency. A much bigger 'bend for your buck,' I guess you could say."

Other participants included researchers from Penn State University; the University of California, Berkeley; the University of Michigan; Cornell University; and Argonne National Laboratory.

* S.H. Baek, J.Park, D.M. Kim, V.A. Aksyuk, R.R. Das, S.D. Bu, D.A. Felker, J. Lettieri, V. Vaithyanathan, S.S.N. Bharadwaja, N. Bassiri-Gharb, Y.B. Chen, H.P. Sun, C.M. Folkman, H.W. Jang, D.J. Kreft, S.K. Streiffer, R. Ramesh, X.Q. Pan, S. Trolier-McKinstry, D.G. Schlom, M.S. Rzchowski, R.H. Blick and C.B. Eom. Giant piezoelectricity on Si for hyperactive MEMS. Science. Published Nov. 18, 2011. Vol. 334 no. 6058 pp. 958-961. DOI: 10.1126/science.1207186.

** A crystalline alloy of lead, magnesium niobate and lead titanate.

Mark Esser | EurekAlert!
Further information:
http://www.nist.gov

More articles from Power and Electrical Engineering:

nachricht Fraunhofer Researchers Develop High-Pressure Sensors for Extreme Temperature
28.06.2017 | Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM

nachricht Touch Displays WAY-AX and WAY-DX by WayCon
27.06.2017 | WayCon Positionsmesstechnik GmbH

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>