title: Multifunctional 3D printing of heterogeneous hydrogel structures.
abstract: Multimaterial additive manufacturing or three-dimensional (3D) printing of hydrogel structures provides the opportunity to engineer geometrically dependent functionalities. However, current fabrication methods are mostly limited to one type of material or only provide one type of functionality. In this paper, we report a novel method of multimaterial deposition of hydrogel structures based on an aspiration-on-demand protocol, in which the constitutive multimaterial segments of extruded filaments were first assembled in liquid state by sequential aspiration of inks into a glass capillary, followed by in situ gel formation. We printed different patterned objects with varying chemical, electrical, mechanical, and biological properties by tuning process and material related parameters, to demonstrate the abilities of this method in producing heterogeneous and multi-functional hydrogel structures. Our results show the potential of proposed method in producing heterogeneous objects with spatially controlled functionalities while preserving structural integrity at the switching interface between different segments. We anticipate that this method would introduce new opportunities in multimaterial additive manufacturing of hydrogels for diverse applications such as biosensors, flexible electronics, tissue engineering and organ printing.
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.|3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Nadernezhad
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.|3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Navid
authors.initials: N
authors.lastname: Khani
authors.affiliation: 3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.|Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Gözde Akdeniz
authors.initials: GA
authors.lastname: Skvortsov
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.|3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Toprakhisar
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.|3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Ezgi
authors.initials: E
authors.lastname: Bakirci
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Menceloglu
authors.affiliation: Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Serkan
authors.initials: S
authors.lastname: Unal
authors.affiliation: Faculty of Engineering and Natural Sciences, Sabanci University, Orhanli-Tuzla, Istanbul, 34956, Turkey.|3D Bioprinting Laboratory, Sabanci University Nanotechnology Research and Application Center, Orhanli-Tuzla, Istanbul, 34956, Turkey.
authors.forename: Bahattin
authors.initials: B
authors.lastname: Koc