“…Different mechanisms to control soft robot stiffness for safe interaction and minimally invasive applications are gaining increasing interest recently. To this end, stiffness-tuneable structures by granular jamming (Steltz et al, 2010;Jiang et al, 2012;Ranzani et al, 2015) and low-melting point alloys (Cheng et al, 2014;Alambeigi et al, 2016), morphing structures (Kuder et al, 2013), stiffness controllable interfaces by granular (Follmer et al, 2012;Stanley et al, 2016), layer (Kim et al, 2013), and scale jamming (Hadi Sadati et al, 2015;Santiago et al, 2016) are recently investigated. The new interest in the continuum manipulators with stiffness varying and inhomogeneous compound structures indicates the need for further investigation of their modeling and control problems.…”