Berlin 2012 – scientific programme
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MA: Fachverband Magnetismus
MA 17: Magnetic Measurement Methods
MA 17.1: Talk
Tuesday, March 27, 2012, 11:45–12:00, EB 202
Single magnetic particle detection using TMR sensor arrays — •Peter Hedwig1, Camelia Albon1, Alexander Weddemann1,2, and Andreas Hütten1 — 1Bielefeld University, Department of Physics — 2Massachusetts Institute of Technology
Biomolecule detection or biorecognition has gained high interest for medical applications like immunoassays and also in fundamental research to study biochemical processes and transport phenomena. Functionalized magnetic particles and beads as markers open up the possibility for biomolecule detection by using magnetic field sensors like giant-magnetoresistive (GMR) and tunneling-magnetoresistive (TMR) elements.
We present high density TMR sensor arrays with linearised sub-micron elliptical elements and only 1.2 µm distance on the array. In this context we discuss design constraints for TMR sensor arrays for single bead detection in the limits of noise and sensor geometry. Related to this, field and voltage modulation techniques and also Heusler based magnetic tunnel junctions (MTJ) will be presented to improve the signal to noise ratio and therefore the sensitivity of such systems.