Google's diagram in its patent application for a skin tattoo communications device. USPTO Google has filed a patent for an electronic skin tattoo that connects to a mobile device, and can be used as a lie detector.

The tattoo isn't permanent — it's applied to a sticky substance on the skin.

The intent of the device is to allow someone to wear a communications device on their throat, keeping a mobile phone or similar device in their pocket. The tattoo communicates with the device, transmitting conversation. Such a device might make things easier for someone who wants to transmit a conversation but cannot use their hands.

Google's application suggests it might be used by security personnel, perhaps working undercover in noisy environments like sports stadiums or at political demonstrations:

Mobile communication devices are often operated in noisy environments. For example, large stadiums, busy streets, restaurants, and emergency situations can be extremely loud and include varying frequencies of acoustic noise. Communication can reasonably be improved and even enhanced with a method and system for reducing the acoustic noise in such environments and contexts.

The tattoo has a darker side too, according to the application. It can be hooked up to a lie detector:

Optionally, the electronic skin tattoo 200 can further include a galvanic skin response detector to detect skin resistance of a user. It is contemplated that a user that may be nervous or engaging in speaking falsehoods may exhibit different galvanic skin response than a more confident, truth telling individual.

It's not clear from the application why someone might want to operate a lie detector at a remote distance from the person they were testing. But again, undercover operations — in which authorities send in stooges to deal with bad guys — spring to mind.

Or perhaps Google envisions a situation in which the person wearing the tattoo doesn't know they have one?

We first saw this on The Register. Here's a closeup of the Google neck tattoo:

USPTO

Disclosure: The author owns Google stock.