nao e' simples, "verde" e barato o suficiente?...
ou estao apenas com falta de imaginacao?...
https://www.youtube.com/watch?v=Q9qJbNmAf2s
on magnetic (maybe) bearings ... ( also quite useful to compress air )
https://www.youtube.com/watch?v=IANBoybVApQ
lulz ::: "magnetic pixels"...
http://www.polymagnet.com/
or ... what about using monopole radially oriented ring magnets?...
