In September 2016 Apple introduced Apple Watch Series 2 which is rated water resistant 50 meters so that users could leave it on when they're in the pool or ocean. Since a speaker can't be sealed because it needs air to produce sound, Apple invented a new one that lets water in, then uses sound vibrations to force it back out. Today the US Patent & Trademark Office published a patent application from Apple that reveals a new moisture sensor for Apple Watch. Apple's patent describes systems and methods for electrical moisture detection in Apple Watch. Apple notes that a moisture sensor disposed in an interior of the watch may include one or more electrodes and sensor circuitry configured to detect the presence of moisture by detecting a change in an electrical measurement of the one or more electrodes. In response to detection of moisture, the moisture sensor may signal a component of the device to perform one or more actions.

Apple further notes that in some examples, capacitance and/or resistance between a pair of electrodes may be monitored to detect the presence of moisture. In one such example, a pair of hydrophobic coated electrode meshes may be positioned in an acoustic path of a device separated by a water absorbent material.

In various examples, a first electrode may be mounted cantilever to a second electrode and the presence of moisture between the electrodes may pull a free end of the cantilever closer to the second electrode.

In some examples, the presence of moisture may cause bridging of a gap between two or more electrodes to complete a circuit or corrosion of a portion of an electrode to open a circuit.

Apple's patent FIG. 2 shows a cross-sectional view of the device of FIG. 1 illustrating example moisture sensors, taken along line A-A of FIG. 1; FIG. 3B shows the moisture sensor of FIG. 3A in the presence of moisture.

Whether today's invention covers the new water resistance method found in Apple Watch Series 2 or is an updated method is unknown at this time. Apple's patent doesn't mention "sound" or "vibrations" in this patent filing to confirm a connection to the new Apple Watch water resistance method. On the flip side, the timing of the filing would strongly suggest that this is the patent supporting the new Apple Watch in more detail. If Apple talks about a "new moisture sensor" in their 2017 marketing for Series 3, we'll know that it relates back to this patent filing. So time will tell.

Apple's patent application 20170030851 was filed back in July 2015. To review the finer details of this invention, click here. Considering that this is a patent application, the timing of such a product to market is unknown at this time.

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