A dual function conductive nano ink for printed electronics connections

The use of sustainable, multifunctional inks in printed electronics has great utility for various devices, partic-ularly at soft biointerfaces. Here, we discuss the development of a multifunctional nanocomposite ink, termed PS-IO-N ink, designed for applications, principally in the field of flexible and bio-electronics. The ink combines electrically conductive properties with magnetic capabilities, offering a dual-functionality that facilitates both physical and electrical connections. The PSION ink is composed of two main components: poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), a conducting polymer with favorable biocompatibility, and iron oxide (Fe3O4) nanoparticles known for their ferromagnetic properties. The ink is formulated as a stable water dispersion, making it eco-friendly and suitable for aqueous processing. Key findings include the optimization of components to balance electrical conductivity and magnetic behavior, allowing the ink to function as both a physical connector and a conductor. The addition of an adhesion promoter enhances the ink's water stability and surface adhesion. The ink's applicability is demonstrated in various scenarios, such as forming flexible circuits on substrates like paper and silk fibroin, creating temporary magnetic connections for electronic devices, and enabling stable connections to sensors for parameter monitoring. The PSION ink provides an innovative solution for flexible and bioelectronic applications, offering the potential for reversible, adaptable connections in both dry and wet environments.