Chapter 13 - Photoactive resin formulations and composites for optical 3D and 4D printing of functional materials and devices

Abstract

Photopolymerization-based 3D printing techniques, such as stereolithography, digital light processing, continuous liquid interface production, two-photon polymerization, and lithography-based 4D printing, utilize photosensitive polymer resins, which are selectively cured layer by layer using either a laser or digital light projection source. These lithographic 3D printing techniques are being increasingly used to fabricate composite materials and ceramic (Al2O3, ZrO2, etc.) objects. The addition of nano- and microscale fillers into photoresins can, however, result in challenges such as an increase in viscosity of the resin, inhomogeneity due to settled filler particles and light scattering. In this chapter, the fundamental processes involved in photopolymerization-based 3D printing are introduced. Strategies to overcome the aforementioned challenges, such as modification of process parameters, dispersion processes, and surface treatment, will be described. Recent progress in the development of functional photoactivated resin formulations and composites and their applications, ranging from 4D printing to the energy field, is reviewed.