The actual purpose of the technology is for things like warranty claim assessment, repairs, troubleshooting, and product development, according to the patent, which was first noted by Patently Apple. Manufacturers typically need to verify whether a malfunctioning device has actually been immersed in water, or whether a customer simply wants to replace their phone.
"Water exposure is among major reasons that may cause significant malfunction of devices," Apple said in its patent. "Therefore, verification of significant water exposure (or water immersion) is important to manufacturers of the devices."
Using colour-changing tape with dye that dissolves after absorbing a certain amount of water, the device includes a system that helps avoid humidity from triggering a false positive.
The device would be enclosed and provide "at least one visual indication after being immersed in water," the company wrote in the patent. iPhone users will be able to detect water damage by looking at the device, without taking it apart.
Still, the process has its disadvantages, in terms of limited application, device tampering, and complicated inspection process, Apple acknowledged. The detection system is limited to devices that are designed to open easily – so not an iPhone.
Apple has been holding out for a water-damage detection patent since December 2006, a month before the first iPhone was unveiled. There is no word on whether the system will be installed in the next-generation iPhone, or if Cupertino will save it for future incarnations.
It has been a good year so far for Apple's patent files. On Tuesday, the company was granted a patent for a head-mounted display device, similar to the Google Glass project and the recently unveiled Olympus MEG4.0 prototype.
Last month, Apple snagged a patent for swappable camera lenses, less than two weeks before another 27 patents rolled into the California company's offices, including ones for inductive charging, as well as scrolling, rotating, and resizing on touch screens.