A key structure assembly is provided for a mobile computing device. The key structure assembly includes a keycap having at least a first segment and a second segment. A first actuation member extends inward into the housing from the first segment of the keycap, and a second actuation member extends inward from the second segment of the key cap. A substrate including a plurality of electrical connects, including a first electrical contact aligned underneath the first actuation member, and a second electrical contact aligned underneath the second actuation member. The keycap is moveable inward to direct either the first actuation member into contact with the first electrical contact, or the second actuation member into contact with the second electrical contact. One or more sections of material are positioned above the first electrical contact and the second electrical contact. The material for the one or more sections is formed from a material that deforms with inward movement of either the first segment or the second segment of the keycap. A layer formed by a thickness of the one or more sections of material extending over the first electrical contact and the second electrical contact is non-uniform in either dimension or amount of material.