In the past decades, inkjet technology has changed the printing industry by providing a new digital and diverse method of printing. The printing process is based on jetting ink droplets through an orifice, and upon contact of the droplets on the substrate a pattern is formed. So far, inkjet technology has been most successfully implemented in graphic arts, including industrial, wide format printing on rigid and flexible substrates. Recently, there has been an increasing interest in the emerging field of inkjet printing functional materials. The versatility of the inkjet printing technology led to its application in a wide range of fields, such as electronics, displays, solar cells, sensors and even in printing organs.
The inkjet process has many advantages. It is a non-contact process, which is a significant advantage compared to other printing processes. It can be applied to almost any substrate regardless of its composition, morphology, and other properties, by proper tailoring of the ink properties. The volume of the jetted droplets is very small, usually in the range of picoliters, and in general the printing process enables high precision and excellent reliability. In order to obtain successful printing, the inks must have chemical and physical properties which meet the requirements for the specific inkjet printing technology. Therefore, the inks formulations are usually complex and contain a variety of materials (besides the functional material) such as wetting and rheological agents, polymeric binders, dispersants and adhesion promoters, depending on the nature of the particular application.
A review on the general subject of inkjet inks is given in the book: "The chemistry of inkjet inks" edited by Prof. Magdassi.
A major activity in the research group is developing inkjet inks with functional properties, such as conductive inks and transparent electrodes. The inks contain a variety of materials as the functional components, such as metal nanoparticles and carbon nanotubes, dissolved or dispersed metal precursors, glass particles and nanoemulsions.