Design, topology optimization, fabrication and testing of an adjustable compliant slit mechanism

Abstract

To create an X-ray Interferometry test bed a high precision adjustable slit mechanism is needed. Com pliant mechanisms are ideal solutions for such high precision mechanisms. This research presents the design, manufacturing, and testing of such a compliant mechanism. Furthermore, topology optimization is explored and evaluated as an alternative design method to find a novel mechanism that performs better than a traditionally synthesized counterpart. A traditionally designed mechanism was first designed and characterized using a 405 nm laser source and Fraunhofer diffraction analysis. Although optical verification was limited to a minimum slit width of 3 μm, experimental results demonstrate that the traditionally developed design has the potential to achieve dimensional requirements, with demonstrated step sizes of 0.2 μm. Simultaneously, a topology optimization model was developed, implementing penalized strain energy, parasitic displacement, and decoupling constraints, along with a robust formulation, to generate an alternative multi-degree-of-freedom mechanism. Although topology optimization proved a tool capable of producing an alternative compliant mechanism, there is still work to be done to fully mature this synthesis method. The research concludes that the developed mechanism meets the requirements set for the X-ray Interferometry test bed, whilst the topology optimization proves a viable alternative, albeit complex, method for future high-performance iterations.