US firm plans a 5-km-high skyscraper that eats smog
US-based materials science firm Arconic has envisioned a 5-km-high skyscraper coated with a self-cleaning material that absorbs smog. The chemicals in the coating interact with light and water vapor, pulling in pollutants from the air. The skyscraper is estimated to be built by 2062 using 3D printing technology to create walls that would also be able to withstand high winds.