A partially degradable polymeric fiber includes a thermally degradable polymeric core and a coating surrounding at least a portion of the core. The thermally degradable polymeric core includes a polymeric matrix including a poly(hydroxy-alkanoate), and a metal selected from the group consisting of an alkali earth metal and a transition metal, in the core polymeric matrix. The concentration of the metal in the polymeric matrix is at least 0.1 wt %. The partially degradable polymeric fiber may be used to form a microvascular system containing one or more microfluidic channels.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with government support under contract numbers FA9550-10-1-0255, awarded by the Air Force Office of Scientific Research, and DOE ANL 9F-31921, awarded by the Energy Frontier Research Centers (EFRC). The government has certain rights in the invention.