Determination of actuation stress. In literature, the actuation stress of shape-memory polymers is commonly measured at a fixed, uniaxial strain. Since the cross-sectional area changes dramatically as the polymer undergoes a large uniaxial strain, it becomes important to specify the sample dimension that is used to calculate the actuation stress. We found that many literature reports were ambiguous about whether postprogramming or pre-programming dimensions were used. In this work, we sought to avoid this ambiguity.