Unobtrusive Thin-Film Devices and Sustainable Green Electronics

Over the last years, the research on unconventional electronics has paved the way to the realization of devices and systems with bespoke properties, including mechanical flexibility, optical transparency, and environmental sustainability. In this paper, alternative materials and novel fabrication methods to achieve highly-transparent thin-film electronics and green, circular and sustainable devices are summarized. Firstly, the use of optically-transparent materials, such as Indium-Tin-Oxide (ITO) and In-Ga-Zn-O (IGZO), has allowed the realization of imperceptible Thin-Film Transistors (TFTs), as well as ring oscillators, on flexible and stretchable substrates, for unobtrusive, flexible and low-power systems. Secondly, conductive traces are fabricated on recycled paper, acting as a green substrate, by using a CO
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laser for on-skin applications. Moreover, the employment of natural and recyclable materials allows device decomposition in natural solutions (i.e. lemon juice), as well as the use of our paper-based electronic as natural support for plant growth and seed germination in soil.