title: Biomimetic 4D printing.
abstract: Shape-morphing systems can be found in many areas, including smart textiles, autonomous robotics, biomedical devices, drug delivery and tissue engineering. The natural analogues of such systems are exemplified by nastic plant motions, where a variety of organs such as tendrils, bracts, leaves and flowers respond to environmental stimuli (such as humidity, light or touch) by varying internal turgor, which leads to dynamic conformations governed by the tissue composition and microstructural anisotropy of cell walls. Inspired by these botanical systems, we printed composite hydrogel architectures that are encoded with localized, anisotropic swelling behaviour controlled by the alignment of cellulose fibrils along prescribed four-dimensional printing pathways. When combined with a minimal theoretical framework that allows us to solve the inverse problem of designing the alignment patterns for prescribed target shapes, we can programmably fabricate plant-inspired architectures that change shape on immersion in water, yielding complex three-dimensional morphologies.
authors.affiliation: John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: A Sydney
authors.initials: AS
authors.lastname: Gladman
authors.affiliation: John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Elisabetta A
authors.initials: EA
authors.lastname: Matsumoto
authors.affiliation: School of Chemical Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: Ralph G
authors.initials: RG
authors.lastname: Nuzzo
authors.affiliation: John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, USA.|Departments of Physics and Organismic and Evolutionary Biology, and Kavli Institute for NanoBio Science and Technology, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: L
authors.initials: L
authors.lastname: Mahadevan
authors.affiliation: John A. Paulson School of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Cambridge, Massachusetts 02138, USA.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Lewis
mesh_terms: D016880:Anisotropy; D040761:Biomimetic Materials; D002473:Cell Wall / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D008962:Models, Theoretical; D010944:Plants / Q000737:chemistry*
chemical_list: D002482:Cellulose