Infineon Technologies Ag

Stiftung Caesar Center of Advanced European Studies and Research

Stifting Caesar

Alfred Ludwig

Joachim Wecker

Manfred Rührig

Markus Löhndorf

Eckhard Quandt

Eckhardt Quandt

A sensor for measuring mechanical changes in length, in particular a compressive and/or tensile stress sensor, includes a sandwich system with two flat and superposed electrodes separated from each other by a tunnel element (tunnel barrier), in particular an oxide barrier, a current being set up between the electrodes and through the tunnel barrier, one electrode consisting of a magnetostrictive layerwhich responds to elongation, and wherein the contributions of the anisotropies caused by mechanical tension are larger than those from the intrinsic anisotropies, relative changes in system resistance &#x394;R/R larger than 10% at room temperature being attained during elongation.

TMR sensor

A sensor device having a magnetostrictive force sensor is provided. To detect a force, the sensor device contains a TMR force sensor element having a magnetic detection layer of material having a magnetostriction coefficient &#x3bb;&#x2267;|5&#xb7;10|, a magnetically harder reference layer, and a tunnel barrier disposed between these layers. Established in the detection layer is a starting magnetization that relative to the magnetization of the reference layer, which is directed in the direction of force, forms an angle of other than 0&#xb0; and thus is rotated out of its starting position under the effect of the force.

Sensor device having a magnetostrictive force sensor

Growing community of inventors

Bonn, Germany

Alfred Ludwig