Behavior of a magnetic manipulator of biological objects

Deals with manipulation of biological objects in an extremely confined space with a magnetic microactuator. Objects are pushed with a small magnetic particle (100/spl times/100/spl times/20 /spl mu/m/sup 3/) which is moved thanks to a permanent magnet. This device allows us to push micro-objects located in water between two glass panes. The distance between both glass panes is few hundred microns. The precision (1 /spl mu/m) is limited by the pixel size of the camera. We define the dynamic behavior of the manipulator. We also describe the control strategy used to achieve a good precision despite the "stick slip effect".