Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microtechnology: Miniature magnetic switches

15.04.2011
An electromechanical switch using a single magnetic plate delivers superior performance in a tiny package

Transistors are commonly used in electronics as switches to turn an electrical current on or off. For applications that require a very large ratio between the on and off current, however, it is necessary to use mechanical ‘reed’ switches, in which magnetic fields physically move metallic wires (or reeds) towards and away from electrical contact points. As devices become more compact, these mechanical switches need to be miniaturized into small packages, without sacrificing performance.

Min Tang and co-workers at the A*STAR Institute of Microelectronics[1] have now demonstrated a high-performance, ultra-compact version of the mechanical magnetic switch (pictured). Their device consists of a magnetic plate supported by two torsion bars, one on each side. The plate is made from a soft magnetic material of 80% nickel and 20% iron, and is patterned into long, narrow strips. When a magnet is brought close to the device, the strips align with the direction of the magnetic field, tilting the plate down to establish electrical contact between two gold pads. When the magnetic field is released, the torsion bars tilt the plate back to its original position, breaking the electrical contact with the gold pads.

Tang and her co-workers maximized the response of the plate to the magnetic field by choosing appropriate lengths, widths and thicknesses for the strips. This allowed them to use a smaller magnet to actuate the device, which in turn reduced the overall size and power consumption of the switch. The researchers were able to reduce the required magnetic field to 4.8 milliteslas, or about half the field strength required in previous designs. Despite the modest magnetic field strength, they could repeatedly form a reliable electrical connection between the plate and electrical contacs with an on resistance as low as 0.5 ohms and a switching time of close to 2 milliseconds.

The fabrication requirements for this novel switch are particularly simple because the device consists of a single magnetic plate, whereas previous designs require two. This helps in achieving a small footprint of about four square millimeters. Importantly, the researchers demonstrated that the switch has excellent lifetime characteristics of 34 million switching cycles, and strong shock resistance of greater than 500 g. These characteristics make the switch suitable for a variety of personal electronics applications, including laptops, cellular phones and personal data assistants, as well as medical devices like hearing aids and pacemakers. The researchers’ next step is to develop a hermetically sealed package for the switch to support such applications.

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

Journal information

[1] Tang, M. et al. A magnetostatic MEMS switch designed for portable applications. Journal of Microelectromechanical Systems 19, 1131–1139 (2010).

Lee Swee Heng | Research asia research news
Further information:
http://www.research.a-star.edu.sg/research/6305
http://www.researchsea.com

More articles from Physics and Astronomy:

nachricht NASA spacecraft investigate clues in radiation belts
28.03.2017 | NASA/Goddard Space Flight Center

nachricht Researchers create artificial materials atom-by-atom
28.03.2017 | Aalto University

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>