One embodiment of the user interface system comprises: A tactile layer defining a tactile surface touchable by a user and plurality of deformable regions operable between a retracted state, wherein the deformable regions are flush with an undeformable region of the tactile layer; and an expanded state, wherein the deformable regions are proud of the undeformable region. A substrate joined to the undeformable region and defining a fluid port per deformable region and a fluid channel. A displacement device displacing the fluid through the fluid channel and the fluid ports to transition the deformable regions from the retracted state to the expanded state. A first and a second pressure sensor detecting changes in fluid pressure within the fluid due to a force applied to a particular deformable region. A processor determining the particular deformable region to be location of the input force based upon the detected fluid pressure changes.