title: Fabrication of slender elastic shells by the coating of curved surfaces.
abstract: Various manufacturing techniques exist to produce double-curvature shells, including injection, rotational and blow molding, as well as dip coating. However, these industrial processes are typically geared for mass production and are not directly applicable to laboratory research settings, where adaptable, inexpensive and predictable prototyping tools are desirable. Here, we study the rapid fabrication of hemispherical elastic shells by coating a curved surface with a polymer solution that yields a nearly uniform shell, upon polymerization of the resulting thin film. We experimentally characterize how the curing of the polymer affects its drainage dynamics and eventually selects the shell thickness. The coating process is then rationalized through a theoretical analysis that predicts the final thickness, in quantitative agreement with experiments and numerical simulations of the lubrication flow field. This robust fabrication framework should be invaluable for future studies on the mechanics of thin elastic shells and their intrinsic geometric nonlinearities.
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A
authors.initials: A
authors.lastname: Lee
authors.affiliation: Department of Mathematics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: P-T
authors.initials: PT
authors.lastname: Brun
authors.affiliation: Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: J
authors.identifier: http://orcid.org/0000-0002-8682-9535
authors.initials: J
authors.lastname: Marthelot
authors.affiliation: Laboratory of Fluid Mechanics and Instabilities, EPFL, CH1015 Lausanne, Switzerland.
authors.forename: G
authors.identifier: http://orcid.org/0000-0003-0954-5157
authors.initials: G
authors.lastname: Balestra
authors.affiliation: Laboratory of Fluid Mechanics and Instabilities, EPFL, CH1015 Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Gallaire
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.|Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Reis