New Frontiers in Fuel Efficiency

This spring I posted a link to a super fuel efficient spacecraft that made its way to the asteroid Ceres. Instead of a rocket engine, NASA gave it an ion drive.
Well, now a university student in Australia has made an ion drive that is 50% more fuel efficient than NASA's previous record-holder.

The existing record is NASA's High Power Electric Propulsion (HiPeP) with 9,600 seconds, but fueled by magnesium Neumann's drive managed an estimated 14,600 seconds of specific impulse. He says "Other metals have lower efficiency, but higher thrust. So you would need more fuel to get to Mars, but could get there faster."