Design and Manufacture of A Silicone Pendulum for PTB’S Nanoforce Standard Facility

This article presents the design and micro manufacture of a novel silicon pendulum to be used at the German National Metrology Institute (PTB) for the measurement of ultra-small forces. The nanoforce standard facility with the previous pendulum, manufactured by precision engineering methods, together with the constructive requirements are described. The particularities of wet-chemical anisotropic silicon etching and their benefits and challenges when used for the manufacturing of the new pendulum are discussed. Finally, two design variants that were realized are discussed. One of the variants proved to be more robust against variations in the silicon raw wafer material and promises to offer an advantageous replacement for the precision engineered pendulums.