And how about end-of-life?
GaAs? You think it's tough recycling your electronics now?
And what are the breakdown modes (if any) of graphene and carbon nanotubes? At a time when we're finding plastic slivers in animals living in the abyss [1] around volcanic hot spots, it would be nice to see us determining how to safely dispose of new materials before we start integrating them into our environment.
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[1] http://www.vliz.be/imisdocs/publications/251718.pdf