Development of Antimicrobial Envelope for RFID Card

This paper proposes the development of an RFID envelope coated with an antimicrobial material that can stop microorganisms’ growth while the card is still regularly used. Copper is chosen as the antimicrobial material for coating on an envelope made of polyethylene terephthalate (PET) by using DC sputtering. The antimicrobial ability of the proposed envelope is investigated against Escherichia coli (E. coli). The result shows that the survival time of E. coli on the proposed envelope is decreased compared with the PET envelope without the copper thin film coated on. Besides its antimicrobial quality, copper can let radio frequency pass through. Thus, the effectiveness of electromagnetic wave transmission through the proposed envelope coated with different thickness of a copper thin film is tested. To evaluate the performance of the proposed envelope, three experiments which cover the test of the antimicrobial ability of copper thin film, the resistance of copper thin film, and performance of RF transmission of RFID reader and tag are conducted. The results of the three experiments show that a copper thin film can prevent the microorganisms’ growth, the resistance of the copper thin film is decreasing while the thickness of the copper thin film is increasing, and the radio frequency can pass though the proposed envelope.