Patent ID: 11926524
Assignee: IOWA STATE UNIVERSITY RESEARCH FOUNDATION, INC.
Field: Audio-visual technology (Electrical engineering)
Classification: CPC B  G  H | IPC B

Claim 20:
21. A method of fabricating a conductive pattern or circuit in a substrate having a length, width, and thickness comprising:
a. providing a substrate with a predetermined pattern or circuit of three-dimensional structural features in the thickness of the substrate to create three-dimensional open or closed channels in directions of any of the length, width, and thickness of the substrate, the channels having surfaces, (i) wherein the predetermined pattern or circuit is indirectly created in the substrate by (1) creating a mold comprising high resolution three-dimensional microstructural features with heights, widths and thicknesses on the order of several tens of micrometers to several hundreds of micrometers, and (2) creating a negative of the three-dimensional microstructural features of the mold from the mold to create the channels in the substrate, (ii) wherein the substrate comprises a film of a natural or synthetic polymeric material, wherein the film is formed by (1) casting a precursor solution onto the mold by direct pouring, drop casting, or spin casting, (2) dry phase inversion or pore forming agent leaching; and (iii) removal from the mold; and
b. coating at least some of said channel surfaces of selected said channels with one or more layers, each layer created by:
i. controlling of flow of a viscous or solution-form liquid comprising a solute of electrically-conductive materials and a solvent through the selected said channels to control at least partial filling of the selected channels with the liquid by control of:
1. flow direction;
2. flow volume;
3. flow rate; and
4. concentration of the electrically-conductive materials in the liquid; and

ii. removing substantially the solvent;

c. to leave the one or more layers of the solute of the electrically-conductive materials at a controlled thickness and coverage of the surfaces of the selected said channels to create a conductive pattern or circuit based on the coating of the channels.