ModuIar (Werconstrained Weak-Link Mechanism for Ultraprecision Motion Control

Abstract. We have designed and constructeda novel miniatureoverconstrainedweak-linkmechanismthat will . allow positioning of two crystals with better than 50nrad angular resolution and nanometer linear driving sensitivity.The precision and stability of this structureallow the user to align or adjust an assembly of crystals to achieve the same performanceas does a singlechannel-cutcrysta~so we call it an "artificialctiel-mt qstal." Unlike the traditionalkinematic linearspringmechanisms, the overconstrained weak%nkmechanismprovides much higher structure stifhess and stability. Usinga Iaminarstructurecofigured and manufacturedby ehemieal etching and lithographyteebniques, we are able to design and build a planar-shape,high stifhss, high precision weak-linkmeebaniam. In this paper, we present recent developmentsfor the overconstrainedweak-linkmechanism. Applicationsof this new techniqueto synchrotrons radiationinstrumentation are also discussed