Supporting Information Soft Ionic Electroactive Actuators with Tunable Non-Linear Angular Deformation Wangyujue Hong 1,† , Abdallah Almomani 2,† , Yuanfen Chen 1 , Reihaneh Jamshidi 1 , Reza Montazami 1,3,* 1 Department of Mechanical Engineering, Iowa State University, Ames IA 50011, USA 2 Department of Aerospace Engineering, Iowa State University, Ames IA 50011, USA 3 Ames Laboratory, Department of Energy, Ames, IA 50011, USA * Corresponding Author: reza@iastate.edu; Tel: +1-515-294-8733 † These authors contributed equally to this work Keywords: ionic electroactive polymers, electromechanical actuators, soft materials, angular deformation 1. Morphological and Mechanical Characterizations. Figures S1a - S1c show a wedge-shaped thickness profile of the casted PEDOT:PSS layer. Similar to a trapezoid, the highest concentration is in the center, and gradually tapers off along the edge, due to the imperfect fabrication process of the simple drop-cast technique. (a) (b) (c) Figure S1: SEM images of specimen Nafion/1s-PEDOT:PSS/Au, from middle point to edge ((a) - (c)) of PEDOT:PSS layer. For the bilayer laminate with much larger length respect to its width and thickness, the elastic modulus of each layer can be deducted as described by Liu et al. previously [1] . Figure S2 illustrates a bilayer laminate with the length much larger than the other dimensions. The elastic modulus of the entire structure Y e is dependent on the elastic modulus of each layer Y a and Y b as: