The thermally-induced phase separation (TIPS) process is being used to form microporous polymeric membranes for a variety of industrially important applications. Of particular interest are membranes that can withstand high temperatures and harsh chemical environments, and membranes that have narrow pore size distribution. Specific targets are improved membranes for biological separations (such as hemodialysis and virus removal from blood), more robust membranes for industrial process streams, and more efficient separators for lithium ion batteries and NiCd batteries.