Formulation of Conductive Filament Composited of Thermoplastic with Carbon Black for a Simple 3D Printing Electrical Device

The thermoplastic- based conductive carbon black (CB) composite filament was fabricated by extrusion method and explored to manufacture an electrical device by three- dimensional (3D) printing. The achieved electrical line resistance was 150 Omega/cm for a cylindrical wire- shape filament which was extruded through a 1.75 mm diameter nozzle at 205 degrees C by loading pre- composited pellets, which were formulated with thermoplastic acrylonitrile butadiene styrene (ABS) and 20 vol% CB filler in chloroform solvent without any other additive. Conductivity was still lower than those of metal conductors. It has been successfully applied for printing a circuit line having internal resistance. Besides of the circuit line, other circuit elements, such as a switch and a base board, have printed only relying on 3D printing, demonstrating an excellent 3D printing of simple electrical circuit, successfully. Especially, an elastic ABS plastic membrane spring printed and was used for making a power switch with a conducting power contact pad which was also printed with the conductive filament. Characterization of the ABS/CB composite filament has been performed by using scanning electron microscope, differential scanning calorimeter and Fourier transform infrared spectroscopy.