Dual stimuli-responsive, rechargeable micropumps via "host-guest" interactions.

We demonstrate a supramolecular approach to the fabrication of self-powered micropumps based on "host-guest" molecular recognition between α- and β-cyclodextrin and trans-azobenzene. Both hydrogels and surface coatings based on host-guest partners were used as scaffolds to devise the micropumps. These soft micropumps are dual stimuli-responsive and can be actuated either by light or by introducing guest molecules. Furthermore, the micropumps can be recharged through reversible host-guest interaction.