**1. Introduction**

340 Mechanical Engineering

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Traupel, W. (2000). *Thermische Turbomaschinen. Zweiter Band: Geanderte Betriebsbedingungen,* 

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ger, Berlin

In the safe physical human-machine interaction the compliance of technical systems is an elementary requirement (Zinn et al., 2004; Bicchi & Tonietti, 2004). The physical compliance of technical systems can be provided either by control functions implementation and/or intrinsic by structural configuration and material properties optimization (Beder & Suzumori, 1996; Wang et al., 1998). The latter is advantageous because of higher reliability as well as general simplicity of the design and production technologies (Beder & Suzumori, 1996; Ham et al., 2009). In the following we focus on mechanical systems with intrinsic mechanical compliance.

In general the deformability of structures is primarly characterised by their stiffness. Stiffness is the measure of the ability of a structure to resist deformation due to the action of external forces (IFToMM Terminology, 2010). Compliant mechanisms are mechanisms, whose functionality is based on its deformability. The mobility of these mechanisms results from their mostly elastic or plastic deformability (The definition is based on (Bögelsack, 1995; Howell, 2001; Christen & Pfefferkorn, 1998)). For the description of these mechanisms it is advisable to use the compliance instead of the stiffness. The compliance is the reciprocal of stiffness and is defined as the measure of the ability of a structure to exhibit a deformation due to the action of external forces (IFToMM Terminology, 2010). The goal of each engineer is by the design of mechanisms the setting of compliance depending upon the purpose of its application. It should be considered, that the compliance is dependent on a variety of parameters. The optimal design of these mechanisms can be realized only with precise knowledge of the influence parameters and possible types of compliance.
