Design and Topology Optimization of a Novel Normal-Stressed Electromagnetic XY Nanopositioning Stage

A high-precision XY nanopositioning stage is developed by designing a novel normal-stressed electromagnetic actuator (NSEA) and compliant parallel mechanism (CPM). Unlike piezoelectric actuators, the designed electromagnetic actuator operates without physical contact. Unlike traditional bridge-type compliant mechanisms, the material distribution of the CPM is optimized using the bidirectional evolutionary structure optimization (BESO) method. The subchain of single-CPM is regarded as an independent design domain in topology optimization. This article extends the BESO method to the frequency optimization field, incorporating the constraints of the material volume and the global displacement. The theoretical models of the normal-stressed electromagnetic circuit and the compliant mechanism are established and systematically verified via finite element analysis. Besides, to realize the high-accuracy control, a Proportional-Integral-Derivative (PID) controller with a feedforward compensator is applied on each axis, which is then demonstrated by finely tracking of the Archimedean spiral and Lissajous trajectories.