Tattoo circuits

They’re temporary, sure, but these tattoos in Ars Technica are still powerful. Literally. They’re monitors made from tattooed circuits on your skin:

All of the necessary components of the devices, including electrodes, electronic components, sensors, radio frequency communication components, and power supplies, are set within an extremely thin (about 30 ?m) elastic polyester sheet. The sheet has a low elastic modulus (that is, it’s flexible) and no noticeable mass (about 0.09 g), so you have a lightweight, stretchable membrane.

Circuit elements (such as transistors, diodes, resistors) and sensors are constructed with typical materials like silicon and gallium arsenide, but are linked using nanoribbon and micro/nanomembrane elements to allow extremely small but flexible designs.

The authors refer to their approach as an “epidermal electronic system” (EES), which is basically a fancy way of saying that the device matches the physical properties of the skin (such as stiffness), and its thickness matches that of skin features (wrinkles, creases, etc.). In fact, it adheres to skin only using van der Waals forces—the forces of attraction between atoms and molecules—so no adhesive material is required. Between the flexibility and the lack of adhesive, you wouldn’t really notice one of these attached.

Spies of the future are celebrating.