In various implementations, a sensor operates in a force sensing mode by determining an applied force based on a first change in capacitance between first and second electrodes related to compression of a compressible material positioned between while the third electrode functions as a shield and in a proximity sensing mode by sensing proximity of an object based on a second change in capacitance of the third electrode while the first and/or second electrodes function as a shield. In some implementations, a device has a cover glass including a surface having a display area, an edge surface, and a cavity; a touch sensing electrode oriented toward the surface; an electrode positioned in the cavity oriented toward the edge surface; and a processing unit operable to detect touch or proximity of an object to the edge surface based on a change in capacitance between the electrode and the object.