SWITZERLAND/The Next Big Thing in biofuel might involve genetically engineered plants that digest themselves, making it cheaper to turn them into fuel. That's one of the new ideas that Arun Majumdar finds fascinating. As the head of the U.S. Energy Department's ARPA-E -- the path-breaking agency that aims come up with efficient, green energy solutions -- Majumdar said this concept is one of a few dozen that are in the development stage now.