Directed Motion and Cargo Transport Through Propagation of Polymer-Gel Volume Phase Transitions


  • We thank Dr. Benjamin Widom, Dr. Abraham Stroock, Dr. Sol Gruner, Anurag Jain, Vasile Nistor, Hooisweng Ow, and Scott Macfarlane for stimulating discussions. This work was partially supported by the USDA Grant No. 123521 and by the NSF Polymers Program Grant No. DMR-0312913.


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A thermosensitive polymer hydrogel can be used to transport cargo by propagating a volume-phase transition along its length (see Figure; red and blue arrows correspond to localized heating and cooling, respectively). Directional motion with velocities up to 15 μm s–1 for cylinder diameters of approximately 1 mm are recorded. Miniaturization of this device could lead to increased gel speeds and microfluidic and medical applications.