Why do NFC tags not work on metallic surfaces?
The surface to which NFC tags are attached can influence the effect. Why is explained here.
NFC tags communicate via radio waves and draw the required energy from them. Metallic surfaces interfere with this principle: if it is stuck to a metal surface or even encased, the NFC tag is no longer able to absorb the energy of the radio waves in such a way that it works.
The reason for this is that conductive metal shields / deflects the reception of radio waves. In simplified terms, this can be compared to radio reception. It fluctuates with the movement of the antenna, for example near power lines, and does not work at all in shielded rooms. It works best without obstacles. The situation is similar with NFC tags. However, due to the significantly lower amount of energy and frequency, NFC tags are much more sensitive.
As mentioned in "", passive NFC tags work completely without a battery. However, they are dependent on an active counterpart. This supplies the NFC tag with energy (induction) via radio waves in the 13.56 MHz range and stimulates it to communicate. As NFC is designed to consume little energy, even a thin sheet of aluminum foil is sufficient to stop the energy transfer.
If the NFC tag is wrapped in this, it is practically unreadable. Fortunately, there are on-metal tags for sticking to metal surfaces, which enable NFC to function on metal surfaces thanks to an insulating layer.
First published: 19.12.2023 / Updated: 19.12.2023 2023-12-19 2023-12-19