A fluid ejection device includes a flexible membrane and an adhesive layer on the flexible membrane. The adhesive layer includes a first region and a second region extending from the first region. The fluid ejection device includes a piezoelectric material layer including an edge region and a central region. A surface of the edge region of the piezoelectric material layer is substantially coplanar with a surface of the second region of the adhesive layer. The surface of the edge region and the surface of the second region are substantially parallel with the flexible membrane.