Nokia recently issued a patent for a graphene oxide-based sensor for protection of mobile devices against water damages. The sensor will use a graphene oxide sensing film senses moisture content or change in relative humidity and triggers an ultra-fast disconnection of the mobile device from its power source (battery).
The sensor will include a sensor capable of sensing water in liquid or vapor form based on the measurement of large time derivative values. The sensor will comprise of a graphene oxide thin film and two or more electrodes in contact with the thin film. An electronic switch will be connected to the sensor and to a power source that powers the circuitry in the electronic device. The GO can be easily integrated into the sensor as a thin film by printing it on the power source's surface.The film should be less than 100 nanometers thick and could also be spray-coated or spin-coated onto the surface.
The patent also lists other materials that may be used for the creation of the sensor: reduced graphene oxide, graphene, functionalized graphene, fluorographene, molybdenite, boron nitride, tungsten disulphide and more. The technology could also be combines with other water-proofing methods.