RFID Reader with 100 Multiplexed Antennas for Cryogenic Liquid Nitrogen (LN) Medical Applications

Background – Purpose of the Project

Our customer, Cryogatt Systems Ltd has unique RFID tagged consumables that can operate in LN vapour at -196°C.
Eccel had previously developed for them a range of RFID/Reader writer modules to read these tagged LN stored consumable tubes when they were removed from the LN storage vessels.

See this video for a demonstration of one of these previous products developed by Eccel with Cryogatt:  https://www.cryogatt.com/rfid-witnessing-system-for-cryogenic-vial-storage/

The customer now required to produce a RFID reader/writer that could read/write to a container of 100 tubes whilst the container was kept within a LN bath at -196°C.

Challenges to Address

The new requirement was for a RFID reader/writer device for 100 vials to be developed that could operate for several hours (minimum 4 hours and ideally 8 hours) within a LN bath used for building and committing cryogenic gene therapy and bio-banking etc applications.

Building and using biological materials samples within a LN bath environment would remove the sample warming that occurs if the storage vessels are placed in room temperature conditions to do this.

This requirement presented a temperature environment that is well outside of the operating range of the electronics and materials used in the construction of such products.

Technology Developed – RFID Reader with 100 Multiplexed Antennas

The custom product that we have developed for our partner Cryogatt Systems has a multiplexed antenna array of 100 antennas connected to a reader board that interfaces using Wi-Fi to an external PC host system running software from our partner, Cryogatt Systems.  All 100 samples can be read in approximately 1 second.

Lithium-ion rechargeable batteries power the unit and thermal heat generating pads to keep the interior of the unit at operating temperature for the batteries and electronics.  These batteries are charged by contactless inductive charging by placing the unit on a charger base station, that Eccel also developed, outside of the LN environment.

The reader can be continuously used for up to 8 hours for creation of cryogenic storage of biological samples in a Liquid Nitrogen sample preparation bath.  The reader can then be recharged in around 6 hours by placing it on the charger base station.

The unit is completely sealed and requires no external physical connections for data transmission (done by Wi-Fi) or battery charging (done by inductive charging).

Due to the quality of insulation and the internal heating pads the electronics inside the unit is kept between 10°C and 25°C whilst the external temperature is close to -196°C.

The very low heat loss from the thermally efficient case (which Eccel also developed) ensures there is no heating of the biological samples in the storage tubes and energy usage is minimised to enable an 8-hour operating cycle time between charges.