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 Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State

nachricht What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto

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: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

Im Focus: Fraunhofer ISE Develops Highly Compact, High Frequency DC/DC Converter for Aviation

The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

UTSA study describes new minimally invasive device to treat cancer and other illnesses

02.12.2016 | Medical Engineering

Plasma-zapping process could yield trans fat-free soybean oil product

02.12.2016 | Agricultural and Forestry Science

What do Netflix, Google and planetary systems have in common?

02.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>