Making multi-layer micro-wire structure

1. A method of making a multi-layer micro-wire structure, comprising:

providing a substrate having a surface;

forming a plurality of micro-channels in the substrate;

providing a first material composition and providing a second material composition different from the first material composition, wherein the first material composition is electrically conductive and the second material composition is electrically conductive;

coating the first material composition over the substrate surface and in the micro-channels;

removing the first material composition from the substrate surface leaving some first material composition in the micro-channels;

coating the second material composition different from the first material over the substrate surface, in the micro-channels, and over the first material composition in the micro-channels;

removing the second material composition from the substrate surface leaving some second material composition in the micro-channels;

curing the first and second material compositions in the micro-channels in a common step to form a cured first material layer and a cured second material layer in the micro-channels; and

wherein the cured first material layer and the cured second material layer form an electrically conductive multi-layer micro-wire in each micro-channel, and wherein the cured first material layer is more electrically conductive when cured than the cured second material layer and the cured second material layer is more light absorbing when cured than the cured first material layer.

2. The method of claim 1 , wherein the first and second material compositions include common materials or first and second material layers include common materials.

3. The method of claim 2 , wherein the first and second material compositions include conductive particles or the first and second material layers include conductive particles.

4. The method of claim 1 , wherein curing the first and second material compositions includes heating or drying the first and second material compositions or sintering or welding conductive particles in the first and second material compositions together.

5. The method of claim 1 , wherein the cured first material layer is adhered to the cured second material layer.

6. The method of claim 1 , wherein either the cured first material layer or the cured second material layer is light absorbing.

7. The method of claim 1 , further including:

providing a third material composition;

coating the third material composition over the substrate surface and micro-channels;

removing the third material composition from the substrate surface leaving some third material composition in the micro-channels;

curing the third material compositions in the micro-channels to form a cured third material layer; and

wherein the cured first material layer, the cured second material layer, and the cured third material layer form an electrically conductive multi-layer micro-wire in each micro-channel.

8. The method of claim 7 , further including curing the first, second, and third material compositions in a common step.

9. The method of claim 1 , further including adhering the cured first material layer to the cured second material layer.

10. The method of claim 1 , wherein the first material composition is immiscible with the second material composition, is more viscous than the second material composition, or has a higher specific gravity than the second material composition.

11. The method of claim 1 , further including at least partly drying the first material composition before the second material composition is coated.

12. The method of claim 1 , further including at least partly but not completely curing the first material composition before the common curing step.

13. The method of claim 1 , wherein removing first material composition from the substrate surface includes removing some but not all of the first material composition from the micro-channels.

14. The method of claim 1 , further including curing the first and second material compositions at least partially by radiation.

15. A method of making a multi-layer micro-wire structure, comprising:

providing a substrate having a surface;

forming a plurality of micro-channels in the substrate;

providing a first electrically conductive material composition;

providing a second electrically conductive material composition that is different from the first material composition;

coating the first electrically conductive material composition over the substrate surface and in the micro-channels;

removing the first electrically conductive material composition from the substrate surface leaving some of the first electrically conductive material composition in the micro-channels;

coating the second electrically conductive material composition over the substrate surface, in the micro-channels, and over the first electrically conductive material composition in the micro-channels;

removing the second electrically conductive material composition from the substrate surface leaving some of the second electrically conductive material composition in the micro-channels; and

curing the first and second electrically conductive material compositions in the micro-channels to form a cured first material layer and a cured second material layer in the micro-channels, wherein the cured first material layer and the cured second material layer form an electrically conductive multi-layer micro-wire in each micro-channel, and wherein the cured first material layer is more electrically conductive than the cured second material layer and the cured second material layer is more light absorbing than the cured first material layer.