Carbon 3D are successfully using oxygen and UV light to grow solids from a pool of liquid resin. The process is called Continuous Liquid Interface Production or CLIP for short.
The resin solidifies when subjected to UV light whilst adding oxygen inhibits the production process. Perfectly smooth surfaces on a solid emerge up to 100 times faster than using fused decomposition modelling (FDM). It is a revolutionary 3D printing process in all senses of the word.
Above is just a marketing clip if you excuse the pun but the video is quite beautiful to watch. The music matches perfectly too – very serene. To learn what is behind CLIP then a complete blog post is given here 3D Printing CLIP Technology – Carbon3D. The 3rd video at the bottom of the page by Science magazine is stunning – your eyes are not being fooled.
Update: It has recently been reported that Carbon 3D will get $100M backing from Google for its revolutionary 3D printing technology.