Abstract: The invention relates to chemical reactor templates having channel-like voids parallel to the template's major axis. The channel-like voids may have either micro-scale or nano-scale cross sectional areas. The chemical reactor templates may be used to produce micro- and nano-scale filaments and particles which have a variety of uses. In some embodiments a chemical reactor template of the invention have at least two intersecting channel-like voids substantially parallel to the major axis of said template. The invention also relates to methods for manufacturing a chemical reactor template using sacrificial layers. The chemical reactor templates of the invention may be fabricated to have multiple arrays of channel-like structures as well as vertical elements to provide access to act as contacts for the channel-like voids and materials formed within the template. The invention relates to methods for producing filaments and particles using a chemical reactor template.