Abstract
Printed electronics will play a more and more important role in the electronics industry due to advantages in high-throughput production and customizability in terms of material support and system process. The printing of traces and interconnects, passive and active components such as resistors, capacitors, inductors, and application-specific electronic devices have been a growing focus of research in the area of additive manufacturing electronics. Adaptation of novel 3D-printing technologies and manufacturing methods are potentially transformative in flexible/stretchable/wearable electronics, wireless communications, efficient batteries, solid-state display technologies, and so on. Other than printing new and reactive functional electronic materials, the functionalization of the printing substrates with unusual geometries apart from the conventional planar circuit boards will be a challenge. Building the substrate, printing the conductive tracks, pick-and-placing or embedding the electronic components, and interconnecting them are fundamental fabrication protocols of 2D- and 3D-printing systems, which should be adopted for a more integrated fabrication system. Moreover, adaptive 4D-printed systems have been developed with highly versatile multidisciplinary applications, including medicine, in the form of assisted soft robots, smart textiles as wearable electronics, and other industries such as agriculture and microfluidics. The adaptive 4D-printed systems incorporated synergic integration of three-dimensional (3D)-printed sensors into 4D-printing and control units, which could be assembled and programmed to transform their shapes based on the assigned tasks and environmental stimuli. This chapter gives a brief review on perspectives of various 2D-, 3D-, and 4D-printing methods, and describes the state-of-the-art in printed electronics and their future growth.