They are found wherever other measurement methods fail: magnetic sensors. They defy harsh environmental conditions and also function in fluids. A new procedure is now revolutionizing the production of two-dimensional magnetic sensors: They now only cost half, and production time is reduced by 50 percent.
Where did you have to go? Turn right here – or was it the next turn? A glance at the smart-phone helps: Various apps provide maps and turn them in the right direction, adjusting them to north. Navigation devices are equally »clever«: They too show the right direction even before the car sets off.
This is made possible by a magnetic sensor. It establishes how the device is being held in relation to the earth’s magnetic field. The market is highly competitive: Every cent counts in the price of the sensors. Until now, manufacturers have relied on several cheap one-dimensional sensors. The disadvantage: They are less sensitive and do not work as accurately as two-dimensional models.
In future however, compact two-dimensional sensors could find their way into smart-phones. Researchers from the Fraunhofer Institute for Electronic Nano Systems ENAS, in Chemnitz have optimized the corresponding manufacturing process. »The costs and manufacturing time for two-dimensional magnetic field sensors drop by half«, says Dr. Olaf Ueberschär, group manager at the ENAS.
The reason for this drop in costs lies in the method of production: The scientists produce the sensors from one piece of material – hence in a totally different way than ever before. Because even a one-dimensional sensor needs two microelectronic half-bridges, whose applied magnetic fields point in opposite directions.
As the basic materials specify a magnetization direction, meaning that the magnetic field within them is already aligned, two different pieces of material used to have to be joined – an elaborate and also expensive procedure. Two half-bridge sensors or four pieces of material were required for two-dimensional sensors.
»For the first time we are able to produce not only the full bridges, but also the two-dimensional sensors monolithically – from one piece«, Ueberschär adds. For this purpose, the researchers separate a layer of material off a wafer and etch the desired structure out. The trick lies in the subsequent laser treatment: This enables the scientists to adjust the preferred magnetic directions at will.
Another advantage: The new sensor is not even quite a square millimeter in size, thus being only about half the size as former models. The smaller the mini-chips are, the more applications they are suitable for. For example for magnetic field cameras, containing numerous sensors in several lines and columns, recording magnetic data. If a high resolution is to be achieved, the sensors must be as small as possible – only then do they fit in close proximity to one another and do not mutually interfere.
Magnetic sensor technology is not restricted to smart-phones. It is used wherever adverse ambient conditions prevail and other measurement methods would fail – for instance in fluids or hot oil baths. They are also found in cars, for example in fully electronic gear levers such as are installed in newer vehicles in the center console or on the steering wheel. And in medical diagnostics they are used to trace tropical diseases and other viruses and bacteria.
Experts will present prototypes of the two-dimensional sensors at the Sensor + Test trade fair from May 19 to 21, 2015 in Nuremberg (Hall 12, Booth 12-531 / 12-537). It will however take about another year before the sensors can actually be used in products.
Dr. rer. nat. Martina Vogel | Fraunhofer Research News
COMPAMED 2016 connected medical devices and people
23.11.2016 | IVAM Fachverband für Mikrotechnik
Successfully transferring Industrie 4.0 into reality
21.11.2016 | Deutsches Forschungszentrum für Künstliche Intelligenz GmbH, DFKI
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
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...
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...
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,...
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...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Information Technology
05.12.2016 | Earth Sciences