Improved conductivity of suspended carbon fibers through integration of C-MEMS and Electro-Mechanical Spinning technologies

Carbon microfibers suspended across carbon walls were fabricated by Electro-Mechanical Spinning and subsequent pyrolysis of a SU-8 based carbon precursor. The shrinkage and elongation of these polymer fibers during the pyrolysis process was observed to depend on the height of the supporting walls. We demonstrate that this shrinkage and elongation during pyrolysis strongly influences the resulting carbon electrical properties. Compared to fibers that retained their length during pyrolysis, conductivity was enhanced by a factor of seven after fibers were elongated four times their initial pre-pyrolysis length with a concurrent shrinkage of their diameter by half.