But no prototype. I am not a physicist, but I ran it through a little thought experiement. If it is some sort of standing pressure wave, it would have to move with the piston, that may be possible, but difficult. The problem I see is that any type of wave would hbe dependent on the frequency/speed of the piston in the cylinder. Therefore, it would have to be there across the entire operating range of the engine, not just it's peak power band. That is a large range. If it falls off anywhere along this range then you get oil control issues, compression issues, or both just as if you had bad rings. Oil control leads to plug/combustion chamber issues and expensive oil replacement. Compression issues lead to huge ineffeciencies, that would offset some or all of the gains from reducing friction. In addition, while the friction may be less, this pressure wave would by its nature have to exert some pressure on the piston and cylinder walls to seal. It may be less friction and less metal to metal contact, but not zero friction. In short a laudable goal, but seems more like a funding grab than a workable idea.