Inkjet Printing for Materials and Devices

TLDR

Inkjet printing, traditionally used for text and images on porous surfaces, has expanded into free‑form fabrication of 3‑D parts and printing of electrical, optical, and biological devices, especially with organic components. This review aims to examine the materials challenges and issues that arise when inkjet printing is used to free‑form and multilayerly fabricate devices and materials. The review discusses the technical requirements for inkjet printing of devices, including higher resolution for organic transistors, pinhole‑free layers to prevent shorting, controlled multilayer mixing or separation, and the shift toward printing on dense substrates.

Abstract

Inkjet printing is familiar as a method of printing text and images onto porous surfaces. In the last few years it has been used as a free-form fabrication method for building three-dimensional parts and is being explored as a way of printing electrical and optical devices, especially where these involve organic components. Inkjet printers are also being used to produce arrays of proteins and nucleic acids. The need for a versatile inkjet technology for free-forming materials and for multilayer devices raises a number of materials problems that do not apply to conventional printing of images. Higher resolutions will be needed if organic transistors are to be printed. Also, it must be possible to print pinhole-free layers to avoid shorting of devices. Multiple layers must be printed such that they mix and react to form a single material or such that they form discrete unmixed layers. Printing on dense rather than porous substrates will be the norm. This article reviews the range of materials that has been printed and the issues that arise as the ink interacts with the substrate.