Four-dimensional photonic micro-actuators for microfluidics applications

With the advent of two-photon polymerization direct laser writing (TPP-DLW) the generation of high resolution three-dimensional (3D) microstructures with arbitrary shapes has increased dramatically. However, the fabrication of stimuli-responsive photoresists, essentially creating four-dimensional (4D) microstructures, remains a significant challenge. Herein, we present a supramolecular cholesteric liquid crystalline (CLC) photonic-photoresist for the fabrication of 4D photonic micro-actuators with sub-micron resolution. These structures display structural color and shape changes which are triggered by variation of humidity and/or temperature. These results embody the advantages of merging self-ordering systems with TPP-DLW to fabricate novel dual-responsive microstructures which hold potential for the development of micro-robots or as sensing elements in microfluidic devices.