US Patent 7764416 - Nanoparticle electrochromic display

http://www.freepatentsonline.com/7764416.html

Electrochromic materials have color-changing properties based on electrically induced chemical processes. This patent from 3M teaches how nanoparticles can be used to enhance the uniformity of electrochromic films. Claim 1 reads:

1. An electrode comprising:

a substrate having a first and a second surface;

a conductive layer;

a multilayer structure comprising alternating layers of at least one polymer layer and at least one layer comprising a dispersion of electroactive chemical bound nanoparticle;

wherein the conductive layer is disposed on the second surface of the substrate, and the multilayer structure is disposed on the conductive layer.