Cost-efficient laser direct writing of flexible electrodes using metal matrix composites

This paper introduces a cost-effective laser direct writing method for fabricating flexible electrodes. Micron-sized copper powder is combined with polypropylene (pp-Cu) and Loctite® Extreme Glue (glue-Cu) to create a metal-polymer composite feedstock. A low-power carbon dioxide laser is used to process the feedstock to build conductive pathways along the laser ablation toolpath. The laser-processed electrode made from the pp-Cu composite exhibits a resistance of approximately 20MΩ, while the glue-Cu electrode demonstrates a resistance of around 2kΩ. Further, the bent electrode retains its conductivity at a bending radius of 30 mm, demonstrating its potential for use in flexible sensor applications. This approach enables the fabrication of flexible and conformal electronics without requiring protective gases, using a cost-efficient laser system.