BBC News

In pictures: Ultra-light material

image captionScientists at Zhejiang University in China have developed an ultra-light material known as carbon aerogel. The scientists behind it claim it is the lightest material ever manufactured.
image captionIt is so light that a slender grass known as Setaria can easily bear its weight without visibly bending. Although the material is in a solid state, it contains many internal pores filled with air - explaining its minimal density. The research is described in the journal Advanced Materials.
image captionTo produce the spongy substance, a team led by Professor Chao Gao freeze-dried solutions of carbon nanotubes and graphene to remove the moisture while retaining integrity. It is just lighter than a record-breaking graphite aerogel made by German researchers in 2012.
image captionDespite its fragile appearance, the aerogel has excellent elasticity, bouncing back when it is compressed. It could also clean up oil: while many oil absorbing products soak up about 10 times their weight in organic solvent, the new material can absorb up to 900 times its own weight.
image captionProf Chao Gao (standing) says carbon aerogels could play an important role in cleaning up oil spills, in water purification and air purification. He adds that the freeze-drying technique they used makes manufacturing it more convenient than traditional methods.
image captionThe new aerogel joins other lightweight materials such as this metallic micro-lattice that is 100 times lighter than styrofoam. The lattice of interconnected hollow tubes was developed by a California-based team and can recover its properties after being placed under extraordinary strain.