This　paper　presents　a　topology　optimization　method　of　compliant　grippers　considering　stress　constraints.　The　proportional　topology　optimization　(PTO)　algorithm　is　applied　to　the　design　of　compliant　grippers,　and　it　is　improved　by　introducing　weight　factors　into　the　objective　function　and　adding　stress　conditions　on　the　basis　of　constraints.　In　the　current　gradient　modeling　of　topology　optimization,　the　global　maximum　stress　is　measured　by　P-norm　function,　and　its　sensitivity　analysis　of　stress　constraints　is　derived　by　adjoint　equations.　It　is　worth　noting　that　more　rigorous　gradient　calculations　are　employed　in　stress　problems　and　their　computation　brings　an　additional　computational　burden.　By　contrast,　the　non-gradient　method　using　PTO　algorithm　allocates　design　variables　to　the　element　proportionally　according　to　the　values　of　stress.　It　can　eliminate　difficulties　in　the　analytical　derivation　and　calculation　of　gradient,　and　improve　the　calculation　efficiency.　Subsequently,　performances　of　compliant　grippers　generated　by　these　two　methods　are　compared　through　finite　element　analysis.　Finally,　the　optimized　compliant　gripper　prototype　is　manufactured　by　three-dimensional　(3D)　printing　using　flexible　thermoplastic　urethane.　Experimental　results　indicate　that　the　non-gradient　method　is　effective,　and　the　optimized　compliant　gripper　has　excellent　characteristics　of　low　stress　and　high　output　performance.　Copyright　©　2025　by　ASME.