Described are support assemblies for a passenger seat, that can include a supportive surface configured to connect with a frame of a passenger seat, and shaped to support a passenger. Supportive surfaces can include a first portion formed of a first plurality of cells having an auxetic cell geometry that can deform to adopt a synclastic curvature under stress, and a second portion formed of a second plurality of cells having a non-auxetic cell geometry that can deform to adopt an anticlastic or cylindrical curvature under stress. The regions having respective auxetic and non-auxetic cell geometries can be arranged to form a supportive surface that can flex to follow contours of a seated passenger.