Inkjet‐Printed Metal Oxide/PEDOT:PSS‐Based Diodes and Rectifiers for Wireless Power Transfer

Abstract

Printed electronic circuits are beginning to attract commercial success in different areas of applications that include low‐cost wearables, biosensors, biomedical tags, packaging, e‐textiles, etc. However, the major part of the research in this domain has always been focused on developing high‐performance thin‐film transistors (TFTs), while the other essential circuit elements, that are required, for example, for low‐loss conversion of the input power, have rarely been reported. In this regard, inkjet‐printed amorphous oxide‐based diodes on glass, and flexible polyimide substrates with rectification ratio >104 and operation frequency up to 25 and 15 MHz, respectively, are demonstrated. Next, using the printed diodes’ full‐wave and double half‐wave rectifiers are fabricated to convert input AC signals to DC supply. In addition, wireless power transfer (WPT) is demonstrated, where the input AC signal is wirelessly transmitted from a distance of 3 cm, at 125 kHz. The demonstrated WPT technology can be suitable for invasive implantable devices and standalone systems in multiple mediums. Finally, bending fatigue tests are carried out with the printed diodes on flexible substrates, down to a bending radius of 2.5 mm to demonstrate tensile strain tolerance up to 2.5%.