One embodiment of the disclosure includes an electronic device including an enclosure (214), a button (106), and a processing element (not shown). The button is connected to the enclosure and includes a button cap (234) defining a user input surface, a flexible member (238) having an interior surface (270) and exterior surface. The flexible member is aligned with the button cap and is connected thereto. The button further includes a strain sensor (244) connected to the interior surface of the flexible member, the strain sensor is in communication with the processing element. When a force is exerted on the button cap, the flexible member bends and the strain sensor detects a user input corresponding to the force and provides a signal to the processing element corresponding to the user input. In some embodiments, the button may be substantially or completely waterproof.