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Ultra-precision devices are often operated in hermetically sealed chambers to avoid external disturbances and maximize their performance. The remaining disturbing effects are mitigated through compensation or corrective methods. Compensation is frequently done in form of in-situ fine mechanical adjustments of highly sensitive units. Such adjustment systems utilize electromechanical drives to transform electrical energy into an intended motion. Electric cables are used as energy and signal carriers from an external control unit. The associated disturbing effects limit the adjustability. In particular, cable connections act as mechanical coupling elements, introducing indeterminate and time-varying forces. This paper deals with the conceptual design of a fine adjustment system for ultra-precision devices with an integrated energy storage. A spring-based mechanical energy storage system controlled by an optical signal is found to be the most suitable solution for the targeted field of application. The integration of an energy storage in the adjustment system to avoid electric cables and their disturbance effects will significantly improve the quality and stability of the adjustment and further increase the performance of precision devices.

The "Quantum Electro-Mechanical Metrology Suite" (QEMMS) is being designed and built at the National Institute of Standards and Technology. It includes a Kibble balance, a graphene quantum Hall resistance array and a Josephson voltage system, so that it is a new primary standard for the unit of mass, the kilogram, directly traceable to the International System of Units (SI) based on quantum constants. We are targeting a measurement range of 10 g to 200 g and optimize the design for a relative combined uncertainty of for masses of 100 g. QEMMS will be developed as an open hardware and software design. In this article, we focus on the design of an enhanced moving and weighing mechanism for the QEMMS based on flexure pivots.

In the forthgoing work on a device that enables subatomic resolved highly reproducible positioning, a first prototype is here presented. The entire positioning system including the actuator, sensor and guiding mechanism, is realized as a micro-electro-mechanical system (MEMS) on chip level, based on silicon-on-insulator (SOI) technology. A modular printed circuit board acts as the mechanical as well as the electrical contacting interface for the silicon chip. First variants of a linear positioning system comprising axisymmetric double parallel crank structure are investigated. Pivot joints as flexure hinges with concentrated compliance are deployed. These hinges show minimal rotational axis displacement for small angles of deflection, thus ensuring smallest deviations to a straight-line path of the linear guiding mechanism. An electrostatic comb actuator transmits forces contactless to minimize over constraints. A measuring bridge in differential mode utilizes the same comb structures to measure the table position based on the capacitance change. Estimating the position resolution, limited by the resolution of the capacitive sensor, a measurable step width below 50 pm can be expected. In further steps, the device will be a platform to be equipped with a lattice-scale-based position measurement system according to achieve an even higher resolution and reproducibility.