New flexible tags that communicate with standard touch screens

1 min read

A flexible capacitive identification tag that communicates with standard touch screens (C-touch) has been developed by Imec, TNO, and Cartamundi.

These ‘C-touch tags’ are thin and flexible chips that can be integrated in paper and plastic products. The companies expect them to be used in a wide range of objects such as tickets, certified documents and payment cards. The tagged object can then connect to the internet when it is placed on a touchscreen or vice-versa.

C-touch tags could create the ‘internet of everything’ as everyday objects can be tagged without the need for additional hardware, major reconfigurations or additional costs for the users. It does not require an external antenna, unlike existing RFID technologies such as NFC, as a tiny antenna is part of the chip itself.

“Our C-touch tag paves the way to a multitude of new applications compared to standard RFID or NFC solutions as it takes advantage of the widespread availability of touchscreen readers compared to the limited amount of NFC readers,” explained Kris Myny, principal scientist and R&D team leader at imec. “We are testing the tag system and communication method using a range of different touchscreens from a variety of brands, including Apple, Samsung and Huawei.”

The 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 36bps 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.

Prashant Agrawal, program manager for thin film electronics at imec, added, “These tags provide new possibilities of connecting objects to internet and enabling Internet-of-Everything. Our next steps will be to further improve the performance of the tags, enable new features such as bi-directional communication with touchscreens, and work with companies in developing solutions based on C-touch tags in different application domains.”

This project was executed in the framework of Holst Centre, an open innovation initiative by imec and TNO. It received funding from the European Union’s Horizon 2020 research and innovation program.