This Small Business Innovation Research Phase I project aims to establish the feasibility of a novel moving magnet actuator (MMA) concept that holds potential to simultaneously provide up to 10 millimeter stroke, nanometric motion quality, and high scanning speeds in flexure-based nanopositioning systems. Nanopositioning systems are employed in all scanning probe lithography and microscopy techniques to provide the relative motion between the probe and substrate. However, lack of appropriate actuation technology is one of the primary factors that currently limit the motion range of existing nanopositioning systems to approximately 100 microns per axis, which in turn limits the "workspace" of current scanning probe techniques. To meet the above-stated requirements of stroke, speed, and motion quality, a novel moving magnet actuator concept is proposed which overcomes the limitations associated with traditional MMAs. The innovative use of radial permanent magnets and concentric coils reduces the moving mass, decreases fringing of the flux in the air-gap to provide greater force output, and improves thermal management via use of integrated heat-pipes. In this project, a systematic multi-domain modeling and design framework that includes closed-form and computational analyses will be employed to evaluate and optimize the proposed MMA's performance.
The broader impact/commercial potential of this project is to enable the scale-up of scanning probe lithography and microscopy techniques and enable their use in practical industrial settings. The proposed MMA technology, if successfully demonstrated in Phase I, will provide higher output force while maintaining small moving mass and power consumption, along with better heat dissipation. This, in turn, will enable unprecedented nanopositioning systems, with 10,000-fold larger workspace compared to competing products, at the end of Phase II. These large-range nanopositioning systems will have a transformative impact on direct-write nanomanufacturing techniques such as dip-pen, electron-beam, and focused ion-beam lithography. While these techniques have been used to fabricate optical metamaterials, thermoelectric devices, and diffraction gratings that have shown remarkable physical properties, large-area patterning capability is necessary to scale up these techniques for practical nanomanufacturing. This project will also create an educational impact via partnership with the University of Michigan that will facilitate the training of students.
The outcome of this Small Business Innovation Research Phase I project establishes the feasibility of a novel moving magnet actuator concept to successfully provide up to 10 millimeter stroke, nanometric motion quality, and high scanning speeds in flexure based nanopositioning systems. The results overcome a critical roadblock in meeting the target specifications in large range, high speed nanopositioning systems that HIPERNAP aims to develop and commercialize. In this SBIR Phase I project, HIPERNAP designed, fabricated and tested a functional moving magnet actuator prototype which provides twice the force to power and mass ratio of other available technologies. This enables high speed point to point positioning with a motion resolution of 5nm RMS. Along with the actuator, HIPERNAP also designed and developed diaphragm flexure bearings, optical encoder test-bed, force gauge test-bed, and a novel thermal management system to test and demonstrate the desired actuation performance in an overall nanopositioning system. This work utilized a systematic modeling and design and optimization approach to achieve unprecedented actuation performance in a deterministic manner, in contrast with ad hoc and piecemeal approaches often used traditionally. The above innovations and design knowledge in actuation technology constitute the Intellectual Merit of this Phase 1 project. Based on this successful outcome of Phase I, HIPERNAP will leverage its now-proven and validated innovations in actuation technology, flexure bearings, drivers, and controllers to design and develop multi-axis positioning stages that meet the above-listed target specifications and address customer needs in industrial metrology and inspection applications in the Phase II project.
