Electronic device having a biometric input system including a composite cover element

An electronic device comprising:

• an enclosure defining an opening;
• a bio-authentication button assembly positioned at least partially within the opening and comprising:
• a capacitive sensing component defining a component surface;
• and
• a cap defining a touch input surface and disposed over the component surface, the cap formed from a composite material comprising:
• dielectric particles having a mean particle size greater than or equal to 50 nm and less than or equal to 500 nm;
• and
• a binder comprising a dielectric polymer material;
• and
• a processor positioned within the enclosure, operatively coupled to the capacitive sensing component, and configured to authenticate a user based on an output of the capacitive sensing component.

An electronic device comprising:

• a housing defining an opening along a side surface of the electronic device;
• a touch-sensitive biometric button assembly extending partially through the opening and comprising:
• a biometric sensing component including a sensing layer;
• and
• an exterior package layer defining an input surface of the touch-sensitive biometric button assembly, at least partially encapsulating an outward-facing surface of the biometric sensing component, and formed from a dielectric material comprising:
• 80% to 95% by weight of oxide particles having a mean particle size greater than or equal to 50 nm and less than or equal to 500 nm;
• and
• 5% to 20% by weight of a binder comprising a thermoset polymer material;
• and
• a switch assembly positioned inward of the touch-sensitive biometric button assembly and configured to detect a user press input.