Which is the smallest RFID chip? (in 2022)

Do you want to know which are the smallest RFID chips? Here’s what you should know. They were introduced by Hitachi in 2003, nearly two decades ago. These chips have an impressing dimension of 0.4mm x 0.4mm while being capable of functioning with a radio frequency of 2.4 GHz.
These chips are known as the “Hitachi mu-chips.” It is as small as a speck of dust, making it barely noticeable in your hands. On the other hand, there are powder-type tags that are even smaller.
Hitachi developed the smallest RFID chips and equipped them with a 128-bit ROM.


Each chip stores 38 unique digits (numbers) like the previous version did. These RFID chips were developed with semi-conductor miniaturization technology combined with electron beams. The latter technology was used to write information on the substrate, allowing them to achieve such a small size.
The Hitachi mu-chips have been in production since they were first announced, and their main purpose was to prevent ticket forgery.

About the Hitachi Mu-chip

According to the original press release by Hitachi, which was published on September 2, 2003, the Hitachi Mu-chip is equipped with the following features and capacities:

  • They have a total size of 0.4mm x 0.4mm.
  • Despite being small, the Mu-chip has a built-in antenna that allows external devices to access the information stored in its ROM. Contactless communication is still a prominent feature, but it only works in close proximity.
  • The chips are already equipped with everything they need to function. There is no need for special equipment.
  • These chips are compatible with a wide range of devices if not all.
  • These are the main specifications for the Hitachi Mu-chip, which remains the smallest RFID even after three decades.

Understanding RFID technology

If you’d like to understand why Hitachi decided to create such small chips, it is important to understand the technology behind them. “RFID” stands for Radio Frequency Identification, which is a system utilized to identify products. In essence, they comply with the same function as bar codes. However, unlike the latter, RFID does not use images to identify the tag placed on a product. This technology uses radio frequency waves to communicate with a microchip, which can be mounted on a variety of surfaces.

You may not be able to notice when an RFID is present in a product, but you should know that you may be in touch with at least one pretty much every day. For instance, when automatic payment systems utilize RFID technology. Like this one, many other examples have normalized the use of RFID chips in our everyday lives.
RFID chips are capable of storing a considerable amount of information, making them more advantageous in this regard than bar codes. Additionally, this technology makes it quite complicated to duplicate a product’s authenticity, granting them more security. Let’s also not forget that the information can be read instantly without visual recognition.

Advantages of RFID technology

The main advantage of RFID technology includes instant operations, more security and efficiency. These characteristics allow workers to complete their duties with more efficiency and freedom. Additionally, RFID tags are more durable as there is contactless recognition. If a problem occurs, it is possible to rewrite RFID tags, prolonging their useful life even more.
Essentially, RFID technology allows us to identify products through radio frequency technology. We need an RFID tag to complete the process, which allows us to store, transmit, or identify such data. When it’s time to identify this information, we’ll need an RFID antenna and an RFID reader. The former will identify the tag while the latter will read the content of it at a certain distance.
RFID technology has become one of the most used technologies in the world for these reasons. Its use has been expanding every year, allowing us to add more efficiency to different processes in our daily life.

Types of RFID Chips

We already know the essentials of RFID technology. Now, there are two main types of RFID tags, active and passive.

Active RFID

Active RFID tags have a transmitter and a power source integrated within the tag. They are typically UHF solutions and can be read within a range of 100m, depending on the type. These tags are usually larger and more expensive. They’re usually used in large assets, like vehicles or cargo containers. Sometimes, Active RFID tags are equipped with sensors that can track temperature levels, humidity and similar information of the object where they are integrated.
You can also find two Active RFID tag types:

  • Transponders – These RFID tags only activate whenever the reader transmits a radio signal, which then they will process.
  • Beacons – These types of RFID tags are utilized to track objects in real-time. For instance, these systems are used at shipping docks for large cargo containers.


Passive RFID

Passive RFIDs have a more complex system, as a signal from both the reader and the reader antenna must reach the tag. Thanks to this signal, the tag will be powered on and then will send such energy back to the reader. There are passive RFID tags with different frequency systems.
Unlike active RFID tags, Passive RFIDs are actually very small and quite flexible. These chips or tags can be placed in a wide variety of items. It’s precise to say that the smallest RFID chips at the moment are passive RFID tags due to their functioning. The Hitachi Mu-Chips need to have an external antenna attached to them so external systems can process the information they contain.

A new contender for the smallest RFID chip

While the Hitachi chips are still one of the most-used RFID chips of their kind, in late 2021, a Gen-2 RFID chip with smaller proportions was introduced to the market. It is a 125μm × 245μm chip, and it was first introduced during the IEEE International Conference on RFID, which took place at North Carolina State University.
While these chips are not being used commercially at the moment, don’t be surprised if you read about them in the news after a few years. For now, the Hitachi Mu-chips is still the number one option when it comes to solving problems of this kind.

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