A superelastic alloy microgripper with embedded electromagnetic actuators and piezoelectric force sensors: a numerical and experimental study

This paper presents the analysis, design, and characterization of a superelastic alloy (NiTi) microgripper with integrated electromagnetic actuators and piezoelectric force sensors. The microgripper, fabricated by electro-discharge machining, features force sensing capability, large force output, and large displacements to accommodate objects of various sizes. The design parameters for the embedded electromagnetic actuators were selected on the basis of finite element sensitivity analysis. In order to make the microgripper capable of resolving gripping forces, piezoelectric force sensors were fabricated and integrated into the microgripper. The performance of the microgripper, the integrated force sensors, and the electromagnetic actuators was experimentally evaluated. A satisfactory match between experimental results and finite element simulations was obtained. Furthermore, comparison studies demonstrated that the superelastic alloy (NiTi) microgripper was capable of producing larger displacement than a stainless steel microgripper. Finally, experimental results of optical fiber alignment and the manipulation of tiny biological tissues with the superelastic microgripper were presented. (Some figures in this article are in colour only in the electronic version)