title: Dynamic polymer systems with self-regulated secretion for the control of surface properties and material healing.
abstract: Approaches for regulated fluid secretion, which typically rely on fluid encapsulation and release from a shelled compartment, do not usually allow a fine continuous modulation of secretion, and can be difficult to adapt for monitoring or function-integration purposes. Here, we report self-regulated, self-reporting secretion systems consisting of liquid-storage compartments in a supramolecular polymer-gel matrix with a thin liquid layer on top, and demonstrate that dynamic liquid exchange between the compartments, matrix and surface layer allows repeated, responsive self-lubrication of the surface and cooperative healing of the matrix. Depletion of the surface liquid or local material damage induces secretion of the stored liquid via a dynamic feedback between polymer crosslinking, droplet shrinkage and liquid transport that can be read out through changes in the system's optical transparency. We foresee diverse applications in fluid delivery, wetting and adhesion control, and material self-repair.
authors.affiliation: 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA [2] Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Jiaxi
authors.initials: J
authors.lastname: Cui
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Daniel
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Alison
authors.initials: A
authors.lastname: Grinthal
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Kaixiang
authors.initials: K
authors.lastname: Lin
authors.affiliation: 1] School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA [2] Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA [3] Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA [4] Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Joanna
authors.initials: J
authors.lastname: Aizenberg
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D005782:Gels; D021621:Imaging, Three-Dimensional; D008422:Materials Testing; D011108:Polymers / Q000737:chemistry*; D012997:Solvents; D013053:Spectrophotometry; D013314:Stress, Mechanical; D013499:Surface Properties; D014508:Urea / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D004129:Dimethylpolysiloxanes; D005782:Gels; D011108:Polymers; D012997:Solvents; C013830:baysilon; D014508:Urea