What is "aerographene"

Aerographene or graphene aerogel is, as of March 2013, the least dense solid known, at , less than helium. It is approximately 7.5 times less dense than air. (The cited density does not include the weight of the air incorporated in the structure: it does not float in air). It was developed at Zhejiang University. Allegedly the material can be produced at the scale of cubic meters.