Development of a 5D nanopositioning and nanomeasuring machine concept for precise measurement and fabrication of complex free-form surfaces

Modern nanopositioning and nanomeasuring machines (NPMMs) measure the topography of flat and known, constantly curved structures with high accuracy. However, aspherical and free-form surfaces present significant challenges for the application of these machines. To address this issue, we are developing a five degrees of freedom NPMM that integrates two additional rotary axes while obeying the extended Abbe principle. This development enables precise tool alignment orthogonal to the local slope of arbitrary surfaces. To maximize this capability, we incorporate a tetrahedral mirror stage, which ensures unrestricted lateral tool access and favorable symmetric weight distribution, while adhering to the Abbe principle. Three interferometers provide precise position monitoring. The developed machine achieves a cylindrical working volume of 60mm in diameter and 30mm in height, allowing nanometer-precise measurement and manufacturing of complex geometries. This paper details the design considerations, challenges, and proposed solutions to achieve these ambitious goals.