A Novel Archimedes Planar Springs Flexure Structure for Microforce Actuator

An Archimedes planar spring (APS) with lower stiffness and compact structure is designed for a microforce actuator. The theoretical analysis of the APS stiffness is carried out using the Castigliano's theory and linear elasticity theory of material mechanics. To optimize the structure, the Finite Element Analysis (FEA) is utilized. The theoretically calculated results using the derived stiffness formula agree well with the FEA simulation results. Meanwhile, the dynamic characteristics are simulated, which conforms the stable and reliable properties. The microforce is generated by an electromagnetic system, which is mainly composed of the coil solenoid, permanent magnet and APS. The designed system has a good characteristics with current resolution of 0.2 mA, basing on the experiments. In addition, the conversion rate can be obtained 3.53 μN/mA from the curve between electromagnetic force and the input current.