Fabrication and mechanical characterization of LCVD-deposited carbon micro-springs

Thirty-eight batches of carbon micro-springs were fabricated using laser-assisted chemical vapor deposition (LCVD) at laser powers and ethylene pressures ranging between 300 mW and 700 mW and 400 mbar and 900 mbar, respectively. A scanning electron microscope was used to determine geometrical parameters such as wire diameter, outside coil diameter, spacing, and pitch. The spring rates for nine batches of springs - chosen from the extremes and middle of the ranges - were determined. With the spring rate values, trends regarding the modulus of rigidity and the modulus of elasticity of the carbon material as a function of laser power and precursor pressure were deduced.