The　plasmodium　of　Physarum　polycephalum,　a　large,　amoeboid　cell,　has　attracted　much　attention　recently　due　to　its　intelligent　behaviors　in　pathfinding,　danger　avoidance,　and　network　construction.　Inspired　by　the　biological　behaviors　of　this　primitive　organism,　in　this　study,　we　explore　the　optimization　capability　of　Physarum　polycephalum　systematically　and　present　the　first　Physarum-inspired　obstacle-avoiding　routing　algorithm　for　the　physical　design　of　integrated　circuits.　We　simulate　the　foraging　behaviors　of　Physarum　polycephalum　using　a　novel　nutrition　absorption/consumption　mathematical　model,　thereby　presenting　an　efficient　routing　tool　called　Physarum　router.　With　the　proposed　routing　approach,　for　a　given　set　of　pin　vertices　and　a　given　set　of　on-chip　functional　modules,　a　rectilinear　Steiner　minimal　tree　connecting　all　the　pin　vertices　while　avoiding　the　blockage　of　functional　modules　can　be　constructed　automatically.　Furthermore,　several　heuristics　including　a　divide-and-conquer　strategy,　a　non-pin　leaf　node　pruning　strategy,　a　dynamic　parameter　strategy,　etc.,　are　integrated　into　the　proposed　algorithm　to　fundamentally　improve　the　performance　of　the　Physarum　router.　Simulation　results　on　multiple　benchmarks　confirm　that　the　proposed　algorithm　leads　to　shorter　wirelength　compared　with　several　state-of-the-art　methods.　(C)　2019　Elsevier　Inc.　All　rights　reserved.