But I challenge the assertion 'not using antennas at all'. The aluminium foil is an antenna. It's even a resonant antenna.
Any resonant antenna will give improved selectivity in a high-noise environment. It is the band-selectivity of the antenna that rejects the ambient noise. And mechanical resonances have been used for narrow-band selectivity before - like in SAW filters.
That does not mean I am not deeply impressed by the idea of making an antenna sensitive enough to generate significant mechanical movement from the incident wave - to actually take mechanical energy out of the radiation. I will also cheerfully admit that the fact it gives higher than normal sensitivity is entirely contrary to what I would have naturally assumed. Fantastic effort, lads! Have a gold star.
All new developments in Radio are proper advances in technology. This is far more like science than e.g. dreaming up sliding unlock controls on a touch screen. Look, patent trolls - this is a proper advance!