I'm really excited in what 3D printing will bring us in the near future, especially the 3D organ printing that can very well save millions of lifes, imagine if someone had a crush liver in a car accident, the hospital could just print another liver to replace the crushed one! The possibilities are endless. We may very well see a society that uses 3D printing daily for food production for example, for house manufacturing... If I wasn't investing in blockchain tech I would 100% be investing in 3D printing, along with chips manufacturing(3D printer can probably be used here too and 3D printers need chips, so it would be a combo investment), space-race exploration stocks and water desalinization.