Why normal RFID tag can't work on metal surface and how to do with it?

If you’ve ever tried to attach an NFC sticker to the back of your iPhone or perhaps put a Bluetooth pairing tag on a metal peripheral, you’ve probably noticed that the RFID tag will no longer scan. Even if the NFC RFID tag isn’t directly on metal, just being close to metal is sometimes enough to cause your scan performance to take a dramatic turn for the worst. 

What is happening?

Simply, eddy currents are killing your NFC tag performance. When an NFC reader is attempting to interact with a NFC tag, it produces a radio-frequency electromagnetic field that both powers the tag as well as allowing the reader to communicate with it. When the RFID NFC sticker is affixed to a surface that is not electrically conductive, this process works very well and you get the smooth tag reading performance you expect.

However, something very different happens with the surface is electrically conductive. When a conductive material is placed inside a changing electromagnetic field, a current is induced in the conductor - these currents are called eddy currents. When these eddy currents form, they interfere with the reader and RFID NFC tag’s ability to communicate with each other, resulting in a tag that seems to be unreadable.

How do we solve it?

In order to restore RFID tag communication, we have to use a special iron-containing ceramic material called ferrite. When a sheet of ferrite is placed between the NFC tag and the metal surface, it reduces the interference caused by the surface, allowing us to create a NFC sticker that can be affixed to metal structures while still being readable.

Where to get these RFID NFC tags?

There are two ways to get these RFID anti-metal tags, the most common is to purchase a RFID tag with the ferrite layer already included, although it is also possible to purchase adhesive ferrite “stickers” seperately and combine them when you apply the RFID tag. While just about any rfid tag can be made into a RFID anti-metal tag, due to their specialized nature, they’re often only readily available in a handful of form factors with just a couple of different types of NFC chips. 

Fortunately, We have RFID tags for both methods and if you need help, please let us know, SUNORIENT is a professional China RFID tag manufacturer and supplier, offer you various NFC stickers and RFID anti-metal tags.