bike light

Hey Has anyone been aware of any bike light out in the market powered using piezoelectric harvesting from vibrations? or has heard of any ongoing project on that? I am actually working in making one prototype myself and have encountered some issues regarding power output. The physics behind...

I am thinking to buy a bike light, i happened to see a review video on Youtube , this guy recommended a lamp only costs $19! can't believe that, but according to his video, looks like the bike light is fine, it's from a Amazon shop http://amzn.to/2p8eikd , have you ever tired this kind of cheap...