Flexible tags communicate with standard touchscreens
Research hub, imec, with TNO, and Cartamundi have developed a flexible capacitive identification tag that communicates with standard touchscreens. The C-touch tags can be integrated in a range of paper and plastic based objects such as tickets, certified documents and payment cards. Connection to the internet is established simply by placing the tagged object on the touchscreen or vice-versa.
C-touch tags are thin and flexible chips that have a unique identifier which can communicate via any touchscreen. Smart cards or other objects with embedded C-touch tags can securely interact with mobile phones used worldwide, as well as with the large number of touchscreens integrated in cars, booths, walls, coffee machines and everyday objects, says imec.
No additional hardware and major reconfigurations or additional costs for the users are incurred, confirms imec. The tags offer security thanks to the very short communication range and have the potential to be produced at low cost thanks to the monolithically integrated antenna. Compared to existing RFID technologies such as NFC, the C-touch tag does not require an external antenna. The tiny antenna is part of the chip, making the tag much smaller than current NFC tags. The small size enables C-touch tags to be integrated in all use cases where interaction via touchscreens is feasible, but RFID/NFC tags are either too large or too expensive or where contactless reading is a disadvantage; this can range from board games to providing higher security in payment cards, or to replace difficult to service and manage hardware readers and access control points with easy to service and update apps on standard mobile devices.
The C-touch tag is based on thin-film transistor technology and is powered by a thin-film battery or a thin-film photovoltaic cell that converts light from the touchscreen. The 12-bit thin-film capacitive identification tag achieves up to 36bits per second data transfer rates at 0.6V supply voltage, which is compatible with commercially available touchscreen devices without requiring modifications. The flexible thin-film integrated circuit has a 0.8cm2 on-chip monolithic antenna and dissipates only 38nW of power at 600mV supply voltage.