Biomimetic self-assembly of helical electrical circuits using orthogonal capillary interactions
Authors: David H. Gracias, Mila Boncheva, Osahon Omoregie, and George M. Whitesides
App. Phys. Lett, Vol. 80, no. 15, 2802-2804
Soft matter keywords
By Alex Epstein
Abstract from the original paper
This letter describes the biomimetic self-assembly of mm-sized polyhedra into helical aggregates.
The system used two orthogonal, capillary interactions that acted in parallel. The design of the
self-assembly process, and of the resulting structures, was modeled on the formation and structure
of tobacco mosaic virus. The self-assembled, helical aggregates carried one, two, or four isolated,
Design of the basic unit of the helical assemblies. ~a! Schematic drawing of a wedge-shaped polyhedron. ~b! A drawing of an aggregate containing five wedges. The coplanar angles a and b have values of 66° and 30°, respectively. The arrows indicate the two possible binding sites for an incoming wedge. ~c! A drawing of an aggregate containing six wedges. The angle a8 is out of plane with respect to the angles a, and has a value of 66°. Helical assembly carrying one electrical circuit: ~d! The pattern of copper used ~single-wire pattern!. ~e! The patterned wedge. ~f! A single wedge after solder deposition, prior to assembly. ~g! A photograph of a helix formed from 48 pieces. ~h! Schematic diagram of the helical electrical circuit.
Helical assemblies carrying several electrical circuits. ~a! The pattern of copper used ~dual-wire pattern!. ~b! The patterned wedge. ~c! A single wedge after solder deposition, prior to self-assembly. ~d! A photograph of a helix formed from 20 pieces, carrying one pair of electrically isolated wires. ~e! A photograph of two interdigitated helices, one formed from seven pieces, the other one from ten pieces. Each helix carries a pair of electrically isolated wires. ~f!, ~g! Schematic diagram of the electrical circuits formed in ~d! and ~e!, respectively.