Just curious where you heard Kevin Fu speak about this? I heard about the PowerGuard a while ago but never heard what became of it. If he has talks about the failures they encountered I'd love to hear them, because it's a really cool concept.
I think he gave a talk at Dartmouth College not long after his company pivoted to a new product. The talk was mostly about other research but he also mentioned what was going on with his company. I don't remember the date or location, might have been hosted by Dartmouth's ISTS. You could contact him directly, he's generally open to discussions about his work. I'm sure his contact info is available online.
