Light-Stimulated Permanent Shape Reconfiguration in Cross-Linked Polymer Microparticles.

Reconfiguring the permanent shape of elastomeric microparticles has been impossible due to the incapability of plastic deformation in these materials. To address this limitation, we synthesize the first instance of microparticles comprising a covalent adaptable network (CAN). CANs are cross-linked polymer networks capable of reconfiguring their network topology, enabling stress relaxation and shape changing behaviors, and reversible addition-fragmentation chain transfer (RAFT) is the corresponding dynamic chemistry used in this work to enable CAN-based microparticles. Using nanoimprint lithography to apply controllable deformations we demonstrate that upon light stimulation microparticles are able to reconfigure their shape to permanently fix large aspect ratios and nanoscale surface topographies.