Design and characterization of a linear micropositioner based on solenoid and compliant mechanism

This article presents the development of a linear micropositioner for a micro electrical discharge machine (μEDM). A linear open-loop micropositioner was developed using a solenoid-flexural element architecture. The power system varies the force delivered by the solenoid using the technique of pulse width modulation (PWM). The capabilities of the micropositioner were evaluated by displacing a 1 kg mass over a 30 μm distance, and tracking its position with an linear variable differential transformer (LVDT) with a resolution of 0.5 μm. Experimental data was collected using a data acquisition system developed in LabView. Results show that the micropositioner is capable of achieving accuracies that fall within the limits of uncertainty of the LVDT. The displacement behavior of the micropositioner presents hysteresis due to its electromagnetic constitution and the friction presented by the linear guides that support the working mass. The impact of the open-loop control parameters on the hysteresis of the micropositioner was evaluated over a series of consecutive controlled movements.