Water Immunity

Abstract

Water immunity is required in a number of environments. Dealing with salt water is much more difficult than distilled or tap water. Water causes false touches by creating coupling between electrodes. Water also ambiguates real touches by spreading the touch over a large area. Placing the device at an angle so that the water rolls off the sensor can help, but it can also create false touches along the bottom of the sensor. The combination of using a hydrophobic coating and careful enclosure design can minimize false touches. Touch controllers that use both mutual and self capacitance typically perform better in wet environments.