Nokia patentirala korištenje Grafena u svrhu povećanja vodootpornosti uređaja

Graphene-Nokia-sensor

Vodootporni mobilni uređaji su postali hit posljednjih godina, a Nokia je svoje varijante takvih uređaja predstavila davno prije (Nokia 5210). Međutim vodootpornost nije bila podjednako koncipirana kao kod današnjih uređaja, a Nokia je unatoč prodaji odjela za Uređaje i usluge nastavila istraživati različite njene aspekte. Upravo je objavljen novi patent dodijeljen Nokiji kojim je zaštićeno korištenje Grafena u svrhu poboljšanja vodootpornosti uređaja. Naime s oksidom Grafena bi se premazali djelovi uređaja u blizini spoja s izvorom energije koji bi reagirali na povećanje vlažnosti ili dodir s vodom. Potom bi takav senzor isključio izvor energije i zaštitio uređaj od pregaranja. U biti je Nokia stari koncept gdje cijeli uređaj ne bi bio vodootporan nastavila a kako patent objašnjava upotreba senzora od Grafena nije komplicirana te bi se vrlo brzo mogla primijeniti. U biti ova tehnologija bi se mogla nadovezati na ostale načine poboljšavanja vodootpornosti uređaja i služiti kao posljednja linija obrane ukoliko primjerice popusti vanjska zaštita i/ili hidrofobni premaz.

Evo nekoliko izvadaka teksta iz patenta:

Exemplary embodiments of a device for the protection of a battery-powered electronic device from water are disclosed herein. The device includes a sensor capable of sensing water in liquid or vapor form based on the measurement of very large time derivative values. The sensor comprises (i) a graphene oxide (hereinafter “GO”) thin film and (ii) two or more electrodes in contact with the thin film. An electronic switch is connected to the sensor and to a power source (e.g., the battery) that powers the circuitry in the electronic device. One possible trigger to activate the electronic switch to disconnect the circuitry of the electronic device from the power source may be a measured threshold value of the time derivative of the GO sensor signal.

In the exemplary embodiments of such a device, if the relative humidity suddenly increases up to high values (e.g., up to 90%, or higher than predetermined standard device operating conditions), the value of the electrical impedance of the GO thin film drops exponentially by several orders of magnitude and almost instantaneously. Such an instantaneous response translates into large values of the time derivative of the GO impedance, which makes the electronic switch disconnect the power source from the circuitry of the electronic device prior to the contact the circuitry by liquid water, thereby providing an ultrafast response time with regard to the sensing of water.

 

The GO can be easily integrated into the sensor as a thin film by, for example, being printed on the power source. For example, the sensor may be integrated into a battery, e.g., by printing the GO film and the electrodes directly on a surface of the battery. In some exemplary embodiments, the film may less than about 100 nanometers (nm) thick. Due to the two-dimensional nature of GO (which is generally employed in flake form), a GO film having a thickness equal to few atomic layers could be achieved, e.g., by Languir-Blodgett deposition. Other exemplary methods by which the GO film can be formed include, but are not limited to, spray coating and spin coating. By employing such methods, the device can be manufactured at low cost.

In alternate exemplary embodiments, the sensor may comprise materials other than GO, such as graphene oxide, reduced graphene oxide, graphene, functionalized graphene, fluorographene, molybdenite, boron nitride, tungsten disulphide, combinations of the foregoing materials, and the like.

The exemplary embodiments of the apparatuses and methods pertaining to the sensor as disclosed herein can be advantageously considered complementary to other apparatuses and methods that prevent water damage of a mobile electronics device by water-proof encapsulation. Furthermore, the exemplary embodiments as disclosed herein may be used without specialized water-proof containers for a particular mobile electronics device, could be easily integrated with other mobile electronics devices at low cost, and could increase the lifetime of a mobile electronics device while reducing costs due to warranty claims for water damage. Moreover, the exemplary embodiments as disclosed herein could improve the robustness of mobile electronics devices and reduce chances of water damage occurring, thereby improving brand perception and trust.

Inače Nokia je predvodnik u istraživanju Grafena, revolucionarnog novog materijala, i već je plasirala nekoliko patenata za njegovu potencijalnu primjenu kod senzora kamere ili pak baterije. Više pročitajte ovdje.

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