78‐4: IGZO‐based Identification Tags Communicating with Everyday Touchscreens

Abstract

In this work, we demonstrate a capacitive coupled data transfer with flexible thin-film electronics using touchscreen as ubiquitous reader interface. The capacitive communication to the touchscreen is proven using a 64-bit metal-oxide thin-film capacitive-coupled identification tag. The tag is powered by a thin film battery or thin-film photovoltaic cell that is converting the light of the screen. The thin-film integrated tag has on-chip monolithic electrodes (0.8cm 2), and the integrated circuit employs 409 transistors and dissipates only 140nW of power at 600mV supply voltage. The asynchronous data rate of the chip is up to 35bps, strictly limited by the touchscreen readout electronics.

Analog and Mixed Signal Circuit Design Techniques in Flexible Unipolar a-IGZO TFT Technology: Challenges and Recent Trends

“…There has been a strong research and industrial effort in a-IGZO TFT technology applications related to large area displays [10]- [13], flexible X-ray imagers [14]- [16], touchscreen tags [17]- [19], Radio Frequency Identification (RFID) [20], [21], Near Field Communication (NFC) tags [22]- [25], machine learning processing engines [26] and flexible microprocessors [8] in the last few years. This research was mainly focused on circuits and systems where the TFTs are used as switches, due to various challenges observed when trying to implement analog functions.…”