Design of a MEMS-Based Nanomanipulator with Sub-Nanometer Resolution

Robotic manipulation at the nanometer (nm) scale requires that nanomanipulators be capable of producing large output forces and nm positioning resolutions. This paper reports on the design of a MEMS-based nanomanipulator with a motion range of plusmn1.15mum and a positioning resolution of 0.017 nm. To our best knowledge, this is the highest motion resolution ever reported. A novel amplification mechanism is employed to convert mum input displacements, generated by a conventional electrostatic comb-drive microactuator, into sub-nm output displacements. The device has a high load driving capability, driving a load as high as 100 mum without sacrificing positioning performance. Based on the pseudo-rigid-body approach, closed-form analytical models of the minification ratio and stiffness of the amplification mechanism are, for the first time developed. Finite element simulation results verify that the theoretical models are valid with an error smaller than 5% and that the mechanism has a high linearity (<0.01%). The novel amplification mechanism and analytical models have general applicability to other MEMS transducer designs. A capacitive position sensor is integrated for detecting input displacements that are converted into output displacements via the minification ratio, allowing closed-loop controlled nanomanipulation. The nanomanipulator finds important applications in the characterization/manipulation of nanomaterials and construction of nano devices. Microfabrication of the nanomanipulator is currently under way