Study on Centrifugal Powder Molding for Microstructure Fabrication: Evaluation of Powder Packing into Microscale Mold

Carbon or Ceramic particles are randomly arranged in conventional functional devices such as fuel cells or Li batteries because they are mainly produced by screen printing or spray coating. Carbon-aligned structures with low tortuosity and larger interface area can possibly improve the performance of such devices because it smoothens mass or proton transfer through membranes and increases active chemical reaction area. The biggest challenge faced while producing a carbon-aligned microstructure is the aggregation of particles, which prevents mold packing. We demonstrated a powder molding method with a centrifugal acceleration varying from 9.8−9.9×104 m/s2. Greater centrifugal force increased the ratio of fulfilled particles. Discrete element method simulation was also performed to clarify the interaction between particles. The simulation results are similar to the experimental results, and they indicate that centrifugal acceleration does contribute to mold packing in this method. This study investigated mold packing, which is the first stage of powder molding.