Fig. 4

a OM images of pMA microparticle-based films at different elongation ratios. The bottom panels show magnified images of the regions indicated by blue circles. Lparticle refers to the major axis of the microparticles. b Stress vs. λmacro curve obtained from the stretching stage, c L particle measured at the positions corresponding to the images in (a) as a function of λmacro, and d a plot of λmacro vs. λparticle; affine deformation: slope = 1