The manufacturing of sensors at Sensitec requires highest precision. (Images: Ralf A. Niggemann)
The manufacturing of sensors at Sensitec requires highest precision. (Images: Ralf A. Niggemann)


Curiosity Meets Opportunity

Wherever movement needs controlling and steering, sensors made by Sensitec are at work even on Mars. The down-to-earth Lahnau company has succeeded in developing ideas that are truly high-flying within a very short time.

On a tour round the Sensitec headquarters in Lahnau you literally have to sharpen your vision. There are no dinner plate-sized products or enormous superstructures to admire. The sensor systems made by the technology company are small, the components and modules tiny, in fact they are often hard to spot with the naked eye. All the same, they have an immeasurable effect, sometimes working under inhuman conditions. For instance, in boreholes almost ten kilometers deep at temperatures hotter than 200 ºC for geological investigations. Or on Mars, where temperatures fluctuate between +27 and -133 ºC.

Sensitec sensor technology on Mars

In Lahnau, Sensitec develops and produces the small, high-precision magnetoresistive sensors used in the “Opportunity” Mars rover. When it landed on the red planet in January 2004, this mobile robot was expected to last for about 90 days. Instead of three months, “Opportunity” has been running for over 10 years, and is still going strong. Meanwhile, it has covered over 40 kilometers – that’s the furthest distance that has ever been traveled on another planet.

The magnificent and sensationally long-lasting performance of the robot on Mars is substantially due to Sensitec sensors. They measure the angles and positions of all moving parts and transmit signals for their control, for instance the angles of the wheels or the suspension of the robotic arm, under the most extreme conditions. Meanwhile, another Mars rover, also equipped with state-of-the-art Sensitec sensor technology, has landed on the planet. Called “Curiosity”, this robot has been sent by NASA to help its older brother “Opportunity” look for extraterrestrial life.

Research and development of magnetoresistive technology

The sensors may be tiny in size, but their contribution to the success of this mission is substantial and fills the Sensitec employees with pride. And it’s easy to picture the similar scenario of the mission of the Lahnau company over 15 years ago when, driven by curiosity and in search of new opportunities, Sensitec was founded in 1999. However, the origins of the company go further back than that. At the end of the eighties, the IHK (Chamber of Trade and Commerce) and a few companies in the region started an initiative to create innovative jobs. This led in 1989 to the founding of the Institute of Microstructure Technology and Optoelectronics (IMO), which went on to focus intensely on the research and development of magnetoresistive technology. The project was very strongly driven by the then president of the IHK, Karl-Heinz Lust, who integrated the institute into the Sensitec GmbH company ten years later.

The new company got off to a successful start and grew at an unstoppable pace. The use of so-called MR sensors in many industrial and automotive series applications was steadily advanced and expanded. In 2004, Sensitec took over naomi technologies AG in Mainz, which had been originally founded by former employees of IBM. Now the company had Europe’s most modern and efficient factory for AMR, GMR and TMR sensors. Four years later, the operative business and the chip production of Sensitec and Sensitec Naomi were consolidated under the umbrella of Sensitec GmbH at the Lahnau and Mainz facilities. Since April 2013, Sensitec GmbH has been part of the Körber Group, an international technology corporation with a workforce of about 11,000 and an annual turnover of more than two billion euros.

Application of the AMR Effect in sensors

“This success story really is based on curiosity and the constant search for new technological opportunities,” says Dr. Rolf Slatter, Managing Partner of Sensitec GmbH. “From the very beginning, these two factors were our key drivers for the further development of magnetoresistive sensor technology.” Yet the basic physics of this technology is already more than 150 years old: the so-called Anisotrope MagnetoResistive Effect (AMR) was discovered by the British scientist William Thomson in 1857. It is based on the knowledge that the electric resistance of a material changes under the influence of a magnetic field. The TMR effect (Tunnel MagnetoResistive) and the GMR effect (Giant MagnetoResistive), which were described much later, are based on a similar principle.

“The application of these principles in sensors only became possible about thirty years ago with thin-film technology. This was when the unique business idea of our company originated,” Dr. Rolf Slatter explains. The properties of the technology he highlights speak for themselves: high precision and resolution paired with dynamics, robustness, reliability, integration capability and energy efficiency. All the same, it took quite a while for industry to recognize the potential of this new technology. But Slatter never gave up: “At the beginning, we had to do a lot of convincing and persuade our customers to reconsider. But our magnetoresistive sensors performed so well that many customers didn’t take much convincing.”

Innovation capability and technological leadership as a basis for business

The breakthrough came in 2009, when the automobile supplier Continental fitted its ABS sensors with magnetoresistive technology. Meanwhile, Sensitec supplies the automotive industry worldwide. Over the years, the performance of the sensors has been further developed across all metrics so that they can be used for a broad variety of applications and in the most extreme conditions – in the automotive sector, in aerospace, in lasers, cameras and medical instruments, and in photovoltaic and wind power plants. “If you like, we have preserved the original character of the institute from which Sensitec evolved to the present day. We are very aware that innovation capability and technological leadership, particularly in our sector, are not luxuries to be afforded but an essential basis of our business,” says Dr. Rolf Slatter.

This is one of the reasons why Sensitec has been involved in numerous national and international research projects for many years, helping to provide the basis for new products and key technologies – in medical or laser technology, in mobility or the energy sector. Some examples of this are the use of special MR sensors to facilitate immunodiagnostics, or the development of magnetoelectronic functional units for industry. Or, as mentioned above, the control of a mobile robot on Mars. It’s hard to tell which of these pioneering developments will be of greatest benefit to mankind. But one thing is certain: a Lahnau company will be playing a major role.


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