Conformations of Super-Elastic Carbon Micro/Nano-Springs and Their Properties

Double-helix carbon micro-springs were prepared by the Ni catalyzed pyrolysis of acetylene containing a small amount of H2S, in high purity (almost 100% among the deposits) and yield (about 20% versus acetylene feed). The conformation and some properties of the carbon micro-springs were examined, and the potential applications were discussed. It was found that they have super-elastic properties, and could be extended to 3-15 times of the original spring axis length and contracted to original state after the load was released. The resistivity increased with increasing extension length, and then got recovery after the load was released. This property enables the microsprings to be used as an advanced bulk sensor material in MEMS. Furthermore, the micro-springs exhibited outstanding electromagnetic wave absorption properties in GHz regions. The conformation of novel single-helix carbon nano-springs prepared by Fe-containing alloys as the catalyst will be also presented.