Article: Odent, J; Wallin, TJ; Pan, WY; Kruemplestaedter, K; Shepherd, RF; Giannelis, EP; “Highly Elastic, Transparent, and Conductive 3D-Printed Ionic Composite Hydrogels”, Advanced Functional Materials, 27 (33)
Abstract: Despite extensive progress to engineer hydrogels for a broad range of technologies, practical applications have remained elusive due to their (until recently) poor mechanical properties and lack of fabrication approaches, which constrain active structures to simple geometries. This study demonstrates a family of ionic composite hydrogels with excellent mechanical properties that can be rapidly 3D-printed at high resolution using commercial stereolithography technology. The new material design leverages the dynamic and reversible nature of ionic interactions present in the system with the reinforcement ability of nanoparticles.
The composite hydrogels combine within a single platform tunable stiffness, toughness, extensibility, and resiliency behavior not reported previously in other engineered hydrogels. In addition to their excellent mechanical performance, the ionic composites exhibit fast gelling under near-UV exposure, remarkable conductivity, and fast osmotically driven actuation. The design of such ionic composites, which combine a range of tunable properties and can be readily 3D-printed into complex architectures, provides opportunities for a variety of practical applications such as artificial tissue, soft actuators, compliant conductors, and sensors for soft robotics.
Funding Acknowledgement: Belgian American Educational Foundation (BAEF); NPRP [5-1437-1-243]; National Science Foundation [CMMI-1537413, DMR-1120296, W911F16-0095]; Army Research Office [W911F16-0095]; King Abdullah University of Science and Technology (KAUST) [KUS-C1-018-02]; Qatar National Research Fund [CMMI-1537413]
Funding Text: J.O. and T.J.W. contributed equally to this work. J.O. gratefully thanks the Belgian American Educational Foundation (BAEF) for its financial support. The authors gratefully acknowledge support from NPRP Grant # 5-1437-1-243 from Qatar National Research Fund, Award # CMMI-1537413 from the National Science Foundation and the Grant ID W911F16-0095 from the Army Research Office. The authors also acknowledge use of facilities at the Cornell Center for Materials Research (CCMR) supported by the National Science Foundation under Award No. DMR-1120296 and the support of Award No. KUS-C1-018-02 made by King Abdullah University of Science and Technology (KAUST). The authors acknowledge Brian Cavelry for providing with the Touchdown the Bear design file.