There are 2.0 million U.S. patents in the map. Patent clusters have been colored here using the colors of the scientific articles to which they are related. A majority of patents are related to electronics and computing (pink), engineering (cyan), and chemistry (blue). Others are related to medicine (light red), physics (purple), or biology (green).
A large group of patents near the middle of map have not been colored using science colors, but are shown in gray. These include things like consumer and industrial products. While these patents do not link to current science, many do, nonetheless, have an older science base.