3. Conductive Materials for Printed Flexible Electronics

Flexible circuits can be produced on polymer film, metal foil, paper, or textile using printing processes and permit futuristic designs with curved diodes or input elements. This requires printable electronic materials that can be printed on the curved substrate surfaces and retain a high level of conductivity during usage even after specified folding and/or stretching. Different materials and their composites have been developed for 3D prinitng and additive manufacturing to fabricate conductive features. These conductive materials could be mainly categorized into metal-based, carbon-based, and organic-based materials as well other conductive materials. The applications have covered photovoltaics, touch screen edge electrodes, automotive and in-mold electronics, PCB, electronic textile and wearable electronics, 3D antennas and conformal printing, EMI shielding, printed sensors, RFID (HF, UHF), TFT and memory, OLED and large-area LED lighting, and more. This chapter will provide an overview of the current status and future trends of typical conductive materials for printed flexible electronics.