@misc{mazurekbudzyska_4dactuators_by_2022, 
author={Mazurek-Budzyńska, M., Behl, M., Neumann, R., Lendlein, A.},
title={4D-actuators by 3D-printing combined with water-based curing},
year={2022},
howpublished = {journal article},
doi = {https://doi.org/10.1016/j.mtcomm.2021.102966},
abstract = {The shape and the actuation capability of state of the art robotic devices typically relies on multimaterial systems from a combination of geometry determining materials and actuation components. Here, we present multifunctional 4D-actuators processable by 3D-printing, in which the actuator functionality is integrated into the shaped body. The materials are based on crosslinked poly(carbonate-urea-urethane) networks (PCUU), synthesized in an integrated process, applying reactive extrusion and subsequent water-based curing. Actuation capability could be added to the PCUU, prepared from aliphatic oligocarbonate diol, isophorone diisocyanate (IPDI) and water, in a thermomechanical programming process. When programmed with a strain of εprog = 1400% the PCUU networks exhibited actuation apparent by reversible elongation ε'rev of up to 22%. In a gripper a reversible bending ε'rev(bend) in the range of 37–60% was achieved when the actuation temperature (Thigh) was varied between 45 °C and 49 °C. The integration of actuation and shape formation could be impressively demonstrated in two PCUU-based reversible fastening systems, which were able to hold weights of up to 1.1 kg. In this way, the multifunctional materials are interesting candidate materials for robotic applications where a freedom in shape design and actuation is required as well as for sustainable fastening systems.},
note = {Online available at: \url{https://doi.org/10.1016/j.mtcomm.2021.102966} (DOI). Mazurek-Budzyńska, M.; Behl, M.; Neumann, R.; Lendlein, A.: 4D-actuators by 3D-printing combined with water-based curing. Materials Today Communications. 2022. vol. 30, 102966. DOI: 10.1016/j.mtcomm.2021.102966}}