Increasing the Efficiency of Thermoresponsive Actuation at the Microscale by Direct Laser Writing of pNIPAM

Thermoresponsive hydrogels such as poly(N-isopropylacrylamide) (pNIPAM) are highly interesting materials for generating soft actuator systems. Whereas the material has so far mostly been used in macroscopic systems, here it is demonstrated that pNIPAM an excellent systems at micrometer scale. Two-photon direct laser writing to precisely structure thermoresponsive scale based on a photosensitive resist. This study systematically shows surface-to-volume ratio of microactuators decisive their actuation efficiency. The phase transition also by nanoindentation experiments. It observed mechanical properties can easily be adjusted process. Finally, found not only total size and surface microactuator play important role, but crosslinking polymer itself. results demonstrate first time systematic pNIPAM-based microactuators, which extended act cooperatively, e.g., microvalves.