![Rachel Armstrong: Architecture that repairs itself?](https://pi.tedcdn.com/r/pe.tedcdn.com/images/ted/126194_800x600.jpg?h=200)
Venice is sinking. To save it, Rachel Armstrong says we need to outgrow architecture made of inert materials and, well, make architecture that grows itself. She proposes a not-quite-alive material that does its own repairs and sequesters carbon, too.