Research 4

Magnetic Biodevices


The employment of micro/nano size superparamagnetic beads (SPBs) as biomolecular tags/labels has recently attracted significant interest as an alternative to commonly used methods such as fluorescent dyes or enzymes due to various advantages. SPBs can be magnetized by an external magnetic field enabling their controlled manipulation like concentration, separation, and transportation as well as their detection by means of magnetic sensors. Another distinct advantage of SPBs is that they lose their magnetization when the external field is removed, which prevents them from agglomerating.
In this project, we are developing conducting microstructors on silicon chips for the the manipulation of SPBs. As current is passed throught the conductors, they attract the SPBs. This effect in combination with customized design of the structures can be used to, for example, concentrate SPBs from a large area to a small area.

Design of an SPB micro concentration device 
with integrated sensing element.

Concentration of SPBs by application of electric current sequentially 

from the outermost structure to the innermost structure.  

GMR sensor element integrated with conducting microstructures for particle concentration and detection.

Concentration of magnetic particles on top of a GMR sensor.

                                                                                         Single particle manipulation.


Dr. Ioanna Giouroudi, Vienna University of Technology, Austria


C. P. Gooneratne, I. Giouroudi, C. Liang, J. Kosel: GMR Ring-Sensor based Microsystem for Magnetic Bead Manipulation and Detection, J. Appl. Phys., 109, 07E517 (2011).

C. P. Gooneratne, C. Liang, J. Kosel: A planar conducting microstructure to guide and confine magnetic beads to a sensing zone, Microelectronic Engineering Journal, 88, pp 1757-1760, (2011).​