Universitaet Kassel

Institut Fuer Physikalische Hochtechnologie E.v.

Universitaet Bielefeld

Universitat Kassel

Arno Ehresmann

Roland Mattheis

Burkard Hillebrands

Guenter Reiss

Juergen Fassbender

Wolfgang-Dietrich Engel

Volker Hoeink

Dirk Meyners

Tim Mewes

Dieter Engel

Jan Schmalhorst

The invention relates to a magnetic multilayer system () which is arranged on a substrate () which is made of a material from the group consisting of a plastic from the group of polymers, metal, metal alloy and paper and/or which is at least one element from the group consisting of a document and packaging. The invention further relates to packaging which comprises such a magnetic multilayer system (). According to the invention, the multilayer system () is used for proving the authenticity of an object. Likewise according to the invention are a method for marking an object with a magnetic multilayer system for proving the authenticity of an object and a method for reading a magnetic multilayer system for proving the authenticity of an object.

Magnetic authenticity feature

A method of transporting a magnetic fluid () or at least one magnetic particle (). The method comprises the steps of: providing a magnetic layer () with an asymmetric re-magnetization property; placing the magnetic fluid () or the magnetic particle(s) () in the vicinity of the magnetic layer () so that they can magnetically interact with the magnetic layer (); and applying an external magnetic field.

Method and apparatus for transporting magnetic fluids and particles

The invention relates to a reconfigurable magnetic logic-circuit array having at least two magnetoresistive elements, each composed of at least two magnetic layers, which are separated from one another by an intermediate layer, in each instance, whereby one of the magnetic layers, as a reference layer, does not substantially change its magnetization under the influence of external magnetic fields, and the other magnetic layer, as a free layer, changes its magnetization perceptibly under the influence of external magnetic fields, and having at least one conductor for signal ports, with which conductor, when current is flowing, a first magnetic field can be generated that flips the magnetization of the free layers, and having a device for on-demand generation of a second variable magnetic field, which also influences the magnetoresistive elements. For this purpose, two such magnetoresistive elements are disposed adjacent to one another, whereby the magnetization of the two reference layers is oriented in opposite directions by means of preadjusted unidirectional anisotropy, and the magnetoresistive elements are interconnected with one another in such a manner that, as a result of the action of the first and second magnetic fields on the magnetoresistive elements, the switching behavior of all basic logic functions, especially the AND, OR, NAND, NOR, XOR or XNOR functions, can be induced on the basis of the resulting changes in the orientation of the magnetization of the free layers, and thus of the resistance of the magnetoresistive elements in the logic-circuit array.

Reconfigurable magnetic logic-circuit array and methods for producing and operating such logic devices

The invention relates to a Wheatstone bridge containing bridge elements that are connected in a conventional manner and consisting of a spin-valve system, in addition to a method for producing the same. The aim of the invention is to produce a Wheatstone bridge, in which respective half-bridges lying adjacent to one another have a respective non-parallel bias magnetisation direction. To achieve this, the respective bridge elements that are not adjacent (or) are provided with a doping of implantable ions in quantities of between 1.10and 5.10atoms/cm2 beneath the pinned ferromagnetic layer of a GMR- or TMR-spin-valve layer system. During the bombardment of selected bridge areas () or surface areas, which are not provided with a covering (), with a low dose of low-energy ions, whose strengths are sufficiently great to enable the is ions to penetrate the pinned ferromagnetic layer, all surface areas or bridge elements () are exposed to a homogeneous, targeted magnetic field of sufficient strength.

Wheatstone bridge containing bridge elements, consisting of a spin-valve system and a method for producing the same

Growing community of inventors

Zweibruecken, Germany

Arno Ehresmann