US Patent 9939783 Water resistant vent in an electronic device

An electronic device includes a compound designed to raise a surface tension of a water-based solution. The electronic device may include a vent feature to allow air to pass through the vent feature such that the air reaches a component in the electronic device. The vent feature may include a first vent structure and a second vent structure, both of which combine to confine the compound. When the water-based solution passes through an electronic device opening, the water-based solution may reach the first vent structure. If a surface tension is sufficiently low, the water-based solution may pass through the first vent structure. However, the water-based solution may then reach the compound causing the compound to dissociate, forming form positive and negative ions that attract molecules of the water-based solution. Then, the water-based solution surface tension increases and does not pass through the first vent structure or the second vent structure.