Novel Zigzag Shape Gives Sensors Magnetic Appeal

Jan 05, 2005
The graphic above shows how the direction of magnetization within a NIST zigzag magnetic sensor follows the shape of the device

Scientists at the National Institute of Standards and Technology (NIST) have designed tiny magnetic sensors in a "zigzag" shape that are simpler in design and likely will be cheaper to make than conventional magnetic sensors used in portable devices. The new sensors could someday be used to measure magnetic fields in applications such as compasses, weapons detection, medicine and non-destructive evaluation of structural materials.
Described in the Dec. 13, 2004, issue of Applied Physics Letters,* the NIST sensors are made of a thin film of nickel and iron and are 35 micrometers long and 5 micrometers wide, with nanoscale design elements at the edges.

The graphic above shows how the direction of magnetization within a NIST zigzag magnetic sensor follows the shape of the device. The green and orange areas of the sensors act like tiny bar magnets with their north and south poles at a 45-degree angle to the centerline of the sensor.

The zigzag design produces the equivalent of many tiny bar magnets oriented with their north and south poles at a 45-degree angle to the centerline of the sensor (see image above). The device senses magnetic fields using a small electrical current sent down the centerline. Tiny changes in the magnetic field surrounding the sensor—such as when a steel weapon passes near it—will increase the resistance to the current and will be detected as an increase in voltage.

Portable magnetic sensors typically include multiple aluminum strips that alternate diagonally across the sensor. The new zigzag sensors are expected to produce clearer signals (less electronic "noise") by confining the current to the center of the device and by eliminating edge imperfections that can result in nanoscale magnetic fluctuations.

The project is part of an interdisciplinary NIST effort to design nanoscale sensors with improved detection levels. NIST scientists experimented with sensor width, length and other dimensions to achieve the desired performance. Engineering of the sensors was supported by theoretical work using NIST-developed imaging and modeling tools.

*F.C.S. da Silva, W.C. Uhlig, A.B. Kos, S. Schima, J. Aumentado, J. Unguris, and D.P. Pappas. Zigzag-shaped magnetic sensors. Applied Physics Letters, Vol. 85, pp. 6025-6027, Dec. 13, 2004.


Explore further: UCI team is first to capture motion of single molecule in real time

add to favorites email to friend print save as pdf

Related Stories

Ion duet offers tunable module for quantum simulator

Aug 06, 2014

Physicists at the National Institute of Standards and Technology (NIST) have demonstrated a pas de deux of atomic ions that combines the fine choreography of dance with precise individual control.

Physicists pay homage to the SQUID at 50

Mar 13, 2014

From humble beginnings in a series of accidental discoveries, SQUIDs have invaded and enhanced many areas of science and medicine, thanks, in part, to the National Institute of Standards and Technology (NIST).

A new era for atomic clocks

Feb 05, 2014

A revolution is under way in timekeeping. Precision timekeeping based on atomic clocks already underpins much of our modern technology—telecommunications, computer networks and satellite-based positioning ...

Recommended for you

And so they beat on, flagella against the cantilever

4 hours ago

A team of researchers at Boston University and Stanford University School of Medicine has developed a new model to study the motion patterns of bacteria in real time and to determine how these motions relate ...

Tandem microwave destroys hazmat, disinfects

8 hours ago

Dangerous materials can be destroyed, bacteria spores can be disinfected, and information can be collected that reveals the country of origin of radiological isotopes - all of this due to a commercial microwave ...

Physicists design zero-friction quantum engine

8 hours ago

(Phys.org) —In real physical processes, some energy is always lost any time work is produced. The lost energy almost always occurs due to friction, especially in processes that involve mechanical motion. ...

Cornell theorists continue the search for supersymmetry

10 hours ago

(Phys.org) —It was a breakthrough with profound implications for the world as we know it: the Higgs boson, the elementary particle that gives all other particles their mass, discovered at the Large Hadron ...

User comments : 0