Analysis of the influence of inertia for non-contact micromanipulation

This article aims at analyzing the effect of the inertia of the objects in remotely actuated systems at the micrometer scale. As the size decreases inertia is commonly neglected and the systems are considered quasi-static. However, this article shows that for high velocities (around 8 mm/s) the dynamic behavior of the manipulated particle must be taken into account. To perform this analysis, a remotely magnetically actuated system dedicated to high speed manipulation is used. 60 mu m-size particles placed at the air/liquid interface are actuated in 2D at different velocities. Precise trajectory tracking is obtained for velocities up to 2.8 mm/s (around 50 body lengths per second), for which inertia can be neglected. For faster velocities (more than 140 body lengths per second demonstrated in this paper) phase lag appears in trajectory tracking: inertia needs to be considered for the control. Experimental results are corroborated by numerical analysis of the model of the system. This article paves the way toward the control of future high speed remotely actuated systems at the micrometer scale.