title: Self-assembly of gears at a fluid/air interface.
abstract: This paper describes a dynamic system-a system that develops order only when dissipating energy-comprising millimeter to centimeter scale gears that self-assemble into a simple machine at a fluid/air interface. The gears are driven externally and indirectly by magnetic interactions; they are made of poly(dimethylsiloxane) (PDMS) or magnetically doped PDMS, and fabricated by soft lithography. Transfer of torque between gears can take place through three different mechanisms: mechanical interaction, hydrodynamic shear, and capillarity/overlap of menisci. Interplay between these forces allows interactions and motions that are not possible with conventional systems of gears.
authors.affiliation: Division of Engineering and Applied Sciences, Pierce Hall, Harvard University, Cambridge, MA 02138, USA.
authors.forename: Jessamine M K
authors.initials: JM
authors.lastname: Ng
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Fuerstman
authors.forename: Bartosz A
authors.initials: BA
authors.lastname: Grzybowski
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides