The ester polymer showed a low stress of 0.4 MPa, similar to rubber (Figure ). The urethane polymer showed a maximum stress of 5.0 MPa at 35 °C. The amide polymer showed a maximum stress of 6.8 MPa also at 35 °C. These values are comparable to a thermoplastic polyurea material reported by Bao et al., which we reproduced and tested to be 5.0 MPa maximum actuation stress at 41 °C. It is worth noting that herein the stress value was determined by pre-programming sample dimensions. As the samples underwent large deformation (> 100%), the cross-section area decreased significantly. When we used the postprogramming sample dimension and 300% strain, we reproduced the same maximum actuation stress of 13.7 MPa as what was reported. Numerical data of actuation stresses using both pre-programming and post-programming dimensions are included in Table .