This was in the news a couple of years ago. It seems far more revolutionary than the engine in the article you posted. No pistons. No need for a transmission. Dramatically lower fuel consumption and weight for the given output power.
At the time it seemed like it was going to change everything in a few years. But googling, it now, there doesn't seem to be any new information. So hopefully Prof. Müller and/or his engine didn't end up in China as well. (I noticed that his Michigan state website is totally out of date.)
I bet a combined opposed piston engine (ref the Junkers Jumo) modified to six strokes (the 5th is compression and then water injection at TDC and the 6th is a steam power stroke) would beat this wave turbine engine in every respect.