Secure dual-chip contactless card with an integrated complementary touch switch

A complementary operating dual-chip contactless card is designed by incorporating an integrated touch switch to avoid potential identity theft.The designed contactless card contains two microchips for a credit card and a transport card. Users can select which card will be used by touching the integrated switch, which is composed of parallel copper plates. By touching the integrated switch with a finger, the impedance of the switch is changed and the power transferred to the microchip is also changed. When the power transferred to the microchip is higher than the threshold power, the microchip is activated. In the normal state, i.e., the untouched state, only the microchip for the transport card is activated. When the switch is touched by a finger, the microchip for the transport card is deactivated and the microchip for the credit card is activated. By incorporating a simple touch switch, the smart card can be under the user's control so that unwanted identity theft or unauthorized credit card charges can be avoided. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:529–533, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27362