An inspection of force reduction in high force electromagnetic tweezers made of FeCo-V foil by laser cutting

Abstract

One of the main goals in the design of magnetic tweezers is to obtain a high force output. In general, the force can be enhanced by adopting materials with high saturation magnetization and by using small sharp structures as magnetic pole tips. However, the practically achieved saturation forces are usually lower than predicted values. In this article, we inspect this issue in detail both by experiments and simulations. Our results show that the observed force reduction can be ascribed to two factors: magnetic performance deterioration near the cutting edges of the tips and a 3D geometrical effect. The high power laser used in cutting causes segregation and morphological roughness near the cutting edge. Moreover, the geometry of the magnetic tips plays an important role regarding the force behavior. As a matter of fact, there is a trade-off among high force, maneuverability, throughput, and manufacturing issues in practical design of magnetic tweezers.