Current Developments in Conductive Nano-Inks for Flexible and Wearable Electronics

Abstract

Nanoparticles are progressively being incorporated into the printing industry and research is underway to enhance their use to boost innovation and competitiveness. Precursors or metallic nanoparticles replace ink pigments in printed electronics, imparting electrical conductivity to the resulting printed patterns. Many types of conductive inks have diverse characteristics that are best suited to specific applications and have different preparation techniques. Conductive inks are a pertinent element of the broader functional printing area, which is currently expanding and is seen as one of the most pertinent future technologies in the printing industry. In this review, the aspects of selecting, functionalizing, and making nanomaterials based conductive inks for printable, flexible and wearable electronics. Various methods and mechanisms for developing conductive inks based on nanomaterials, such as Ag nanoparticles, Cu@Ag core-shell nanoparticles, graphene conductive ink, biocompatible CNT ink, conductive indium tin oxide (ITO), proposed by various research groups are summarized. We have also attempted to provide insights into enhancing printing ink parameters such as uniformity, flexibility, resolution, and durability which are considered to be very important aspects for any printable inks. Finally, the applications of the conductive ink in thin film transistors (TFT), dye sensitized solar cells (DSSC), Radio Frequency Identification (RFID) tags, and sensors are summarized.

Recent progress of patterned electrodes in wearable electronics: fabrication and application

“…To realize the flexibility, stretchability, and adhesion of wearable devices with the human body, distributing the conductive materials of electrodes ordered to make them flexible is a feasible solution. It is a good solution combining conductive materials with soft substrates to improve the stretchability of electrodes [1][2][3][4][5]. At the same time, it can achieve high conductivity, which is similar to that of hard conductors.…”

Tailoring Water-Based Graphite Conductive Ink Formulation for Enzyme Stencil-Printing: Experimental Design to Enhance Wearable Biosensor Performance

“…Previously, conductive inks were primarily used for repairing electrical circuits and were expensive, requiring specific curing procedures involving lengthy preparation times and high temperatures. , Additionally, these inks were typically dispersed in organic solvents, which resulted in lower conductivities and the potential for poisoning biological recognition elements such as redox enzymes, antibodies, and DNA. − However, advancements in technology have led to the development of water-based lab-made inks, which offer comparable electrochemical performance to solid electrodes mentioned in the existing literature. This breakthrough has allowed for the construction of biosensor architectures with improved characteristics. − …”

Eco-friendly alkali lignin-assisted water-based graphene oxide ink and its application as a resistive temperature sensor

“…Inkjet printing is superior to other printing methods in a number of ways, such as higher resolution, versatility, low materials cost, and facile preparation methods [1][2][3]. Conductive ink is the most essential component for inkjet printed electronics, and its composition significantly influences the quality of the printed devices and sensors [4,5]. The most important component in conductive inks is uniformly dispersed conductive fillers in a relevant solvent.…”