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 A big nano boost for solar cells
18.01.2017 | Kyoto University and Osaka Gas effort doubles current efficiencies

nachricht Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>