We all want to find ways to have materials repair themselves. So, when our kids rip their pants, the holes will disappear. Or, when cracks appear in concrete, they will refill the space and keep our structures sound. (Oh, wait, I reported on BacillaFilla some 6 years ago… and, yet- it’s still not commercially available. Such is the promise of research. Which may portend problems for what I plan to discuss today.)