Aerographite has been dethroned as the world’s lightest substance, replaced by a new form of graphene aerogel.
As research into aerogel continues, scientists are discovering ever-lighter variations. First, there was carbon nanotube aerogel, with a density of 4 milligrams per cubic centimetre. Then along came silica aerogel, which weighed in at 1 milligram per cubic centimetre and garnered 15 entries in Guinness World Records. It was ousted by metallic microlattices, at 0.9 milligrams, and then aerographite, at 0.18 milligrams.
Now, a new graphene aerogel created by scientists led by professor Gao Chao at the Zhejiang University has swept past, weighing in at just 0.16 milligrams per cubic centimetre.
For reference, the density of air is 1.2 milligrams per cubic centimetre — so the new material is 7.5 times lighter than air. It’s twice as heavy as hydrogen — the lightest element there is — but beats out helium, which has a density of 0.1786 milligrams per cubic centimetre.