Metal-based high-aspect-ratio microscale structures (HARMSs) are basic building blocks for metallic microdevices such as microelectromagnetic relays and microchannel heat exchangers. Metallic microdevices may have advantages over Si-based devices when subjected to high stresses, high temperatures, and other harsh conditions. In this article, the authors summarize our recent results on molding replication of metal-based HARMS. The micromolding response was experimentally measured in Al and Cu, and rationalized with companion high-temperature tensile testing and finite element analysis. Successful replication of Ni-based and NiTi-based HARMS was demonstrated. (C) 2008 American Vacuum Society.