Inkjet-printed inductively-coupled power harvesting circuits on plastic

University Of California-Berkeley, Berkeley CA

Investigators

Abstract

There has been intensive research focused on the development of an electronic replacement for the ubiquitous UPC barcode. To replace consumer barcodes, ultra-low cost will be paramount. Organic-based circuits may enable this due to their low fabrication cost. In this work, the investigators will develop the technologies necessary for RFID barcode replacement systems, and will use these to demonstrate a major subcomponent of any REID system - the power harvesting subcircuit. Power for barcodes will be supplied by inductive coupling since battery integration is not feasible. To achieve the cost points required for UPC replacement, it is necessary to integrate this and other REID circuitry on existing packaging with little or no perturbation of the packaging process. Specifically, the elimination of the need for lithography, plasma etching, and vacuum evaporation is critical to ensuring adequately low cost. The investigators will use nanocrystal-based and organic-based materials and processes that they have developed to demonstrate high quality active (diodes and transistors) and passive (inductors, wires, and capacitors) components, and will assemble these to fabricate the first functional power-harvesting sub-circuit on plastic. The entire process will be performed at low cost using a custom inkjet printer, eliminating all lithographic and vacuum-based process steps. High-Q Spiral inductors will be fabricated using a novel low-temperature gold nanocrystal inkjetting technology that has been developed by the investigators. Parallel plate capacitors will be formed using nanocrystal electrodes and inkjetted polymer dielectrics. Schottky diodes will be developed using inkjetted gold and silver nanocrystals as the rectifying and ohmic contacts and inkjetted organic semiconductors as the active layer. Transistors will be fabricated by inkjet processing using an existing polythiophene-based process. Finally, the various components will be integrated to form a power-harvesting circuit. An undergraduate and a graduate student will be involved in this work. In particular, the mentoring of the undergraduate student will be emphasized through a series of tutorials and review programs. The results of this proposal will also be used in a University-sponsored highschool outreach program. This will increase the level of interest in science and engineering among local high-school students