noun, Biology. 1. an orientation of an organism to an external stimulus, as light, especially by growth rather than by movement. Origin of tropism. 1895-1900. First recorded in 1895-1900; independent use of -tropism. Related forms. tropismatic.
Friction on as-grown graphene (Fig. 1c) is ultra-low and rather uniform with its magnitude close to the previous reports4. In contrast, friction on graphene after ï¬uorination becomes
1 Chinese researchers showed off their graphene aerogel by balancing it on the petals of a cherry blossom. 2  The sponge-like matter is made of freeze-dried carbon and graphene oxide and is the lightest material ever made.3  Graphene was developed nine years ago by two Russian researchers working at Manchester University. Chinese researchers showed off their graphene aerogel by balancing it on the petals of a cherry blossom. 2  The sponge-like matter is made of freeze-dried carbon and graphene oxide and is the lightest material ever made. 3  Graphene was developed nine years ago by two Russian researchers working at Manchester University.