Chapter 3 - Polymer-based conductive composites for 3D and 4D printing of electrical circuits

Abstract

The formulation of electrically conductive filaments readily compatible with commercially available 3D printers could potentially make additive manufacturing of printed electrical circuits a practical and cost-effective option. Conductive polymer composites (CPCs) prepared from a 3D printable thermoplastic blended with a conductive filler could offer a direct way of realizing usable 3D circuits via fused deposition modeling (FDM). This chapter reports on the recent advances made using carbon black and metal-based fillers to achieve low resistivity (<10−1Ωm) filaments. The material's ability to respond to external stimuli (e.g., electric field, heat, UV light, strain) provides another degree of versatility to realize a host of different circuit elements (e.g., wire, resistor, sensor, etc.) using one single type of filament. Advantageously, with the sufficiently low resistivity attained in such filaments, the circuits printed can be powered by conventional low-power dry cells, highlighting the potential for practical applications in printed electronics and customized wearables. We begin by providing a set of criteria to help assess the state of the art, then we provide a survey of recent works on the basis of these criteria, and conclude by discussing some current challenges and opportunities for further development.