Researchers from Germany’s Fraunhofer Institute for Casting, Composite and Processing Technology IGCV have develop a smart 3D-printed ring that could potentially replace traditional wallets, keys and health insurance cards.

The 3D-printed ring reportedly surrounds a radio frequency identification (RFID) chip that is sealed, invisible and tamper-proof and that can be used to open smart doors, pay for items at a store checkout and even serve as a health insurance card.

Source: Fraunhofer IGCV

To create the ring, researchers used a form of 3D printing dubbed powder bed-based additive manufacturing wherein a laser beam is guided over a bed of fine metal powder. The laser melts the powder, which then solidifies to create a composite material and the remainder of the ring is constructed layer by layer around a cavity where the RFID chip is placed.

To ensure that electromagnetic signals from the RFID chip can be sent through the 3D-printed ring’s metal — which typically acts as a shield against such signals — the team used a frequency of 125 kilohertz. With its shorter range, the signal is less effectively shielded by the metal, according to the researchers.

Additionally, the RFID tag is place just 1 mm below the metal, making signal penetration achievable.

In addition to serving as a wallet or key to connected doors, the researchers suggest that the RFID 3D-printed ring could potentially be used to enter hotel rooms or to hold healthcare associated data such as drug allergies or blood type.