A computer mouse in one embodiment includes an arcuate cover comprising a plurality of projections on a top surface; a capacitance trigger assembly aligned with the projections thereabove and comprising a flexible arcuate first capacitive film and a flexible arcuate second capacitive film therebelow; a printed circuit board disposed under the capacitance trigger assembly and comprising a photodetector array on an underside and a microprocessor; and a base releasably secured to the cover and comprising a light guide. In response to a touch of the projection, a button clicking action is triggered.