[nesu]

Would be good if it were to use more environmentally-friendly materials. The piezoelectric material as described in the article is molybdenum disulfide. This could be a huge disadvantage, since molybdenum is not so abundant in nature (scarcer than lithium). There are already concerns regarding the use of lithium, and whether its availability would be able to sustain global production (rechargeable batteries, mainly) in the next hundred years or so.

I gained a huge interest on piezoelectric materials upon learning of solar piezoelectric thermoacoustic generators. Not really as efficient as solar panels, but could be far cheaper and more environmentally-friendly.