Here are two more from Science Daily:
Making steam with sunlight and nanoparticles at 24% efficiency. I'm picturing a gas/solar hybrid steam engine:
Super-Efficient Solar-Energy Technology: ‘Solar Steam’ So Effective It Can Make Steam from Icy Cold Water
A carbon nanotube twisted up like the rubber band in a model airplane. With both ends fixed you get contractile force like a muscle. With one end fixed you get rotational torque.
Wax-Filled Nanotech Yarn Behaves Like Powerful, Super-Strong Muscle