The tattoo is equipped with screen-printed electrodes and a small hydrogel patch containing pilocarpine, a drug that passes through the skin and induces sweat. Then, the sweat comes into contact with an electrode coated with alcohol oxidase, an enzyme that selectively reacts with alcohol to generate hydrogen peroxide, which is electrochemically detected. A printed flexible electronic circuit board powers the tattoo and can communicate the data wirelessly with a mobile device.
The flexible electronic circuit board connects to the tattoo via a magnet and a user can put on the patch and get a reading that’s well correlated to his or her blood alcohol concentration within a few minutes.
The device can be worn on the skin and could be used by doctors and police officers for continuous, non-invasive and real-time monitoring of blood alcohol content.
With the associated App, such a device could not only give out readings and send an alert to the wearer, but it could also let friends check up on each other before handing over the car keys. Another use case would be to communicate the readout to a car's ignition locking mechanism.
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