Regensburg 2016 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 25: Focus: Functional Polymer Hybrids II

CPP 25.1: Hauptvortrag

Dienstag, 8. März 2016, 14:00–14:30, H51

Plasmonic heating brings dynamic control of microgel shape and locomotion — •Ahmed Mourran, Hang Zhang, and Martin Moeller — DWI-Leibniz Institute for Interactive Materials, and Textile and Macromolecular chemistry, RWTH Aachen University Germany

Hydrogel actuation involves reversible swelling/shrinkage of the polymer network. However, the volume change of hydrogel is a slow diffusion-controlled process with a strong dependence on size. For this reason, hydrogels materials hardly allow instant control of their shape, making it difficult to develop fast and soft actuators. To overcome this limitation, we have combined non-equilibrium inhomogeneous swelling/shrinkage and anisometric microgel geometry to achieve large and fast bending deformations. An essential finding of this work is the generation of non-reciprocal actuation, i.e., each cycle consists of a forward and a distinct reverse movement, thereby creating the thrust needed to propel the hydrogel microswimmer in water. A body shape deformation is triggered by the photothermal heating of gold nanorods embedded in a temperature sensitive microgel. Absorption of high-intensity laser light by the plasmonic nanoparticles allows rapid heating and makes it possible to achieve fast dynamics. We will show that dynamic control of shape through plasmonics heating represents an exciting avenue in the development of photo-thermo-mechanical actuator or maneuverable soft microswimmers.