The emergence of reversible–deactivation radical polymerization in 3D printing

The majority of materials 3D printed using vat photopolymerization techniques are prepared by uncontrolled polymerization methods and cannot be easily modified to introduce additional functionality; these materials can be considered as effectively “dead” materials. Fortunately, a suite of photocontrolled reversible–deactivation radical polymerization (photoRDRP) techniques is recently implemented in 3D printing. In addition to their fast polymerization rate and oxygen tolerance, the high livingness imparted by photoRDRP methods is beginning to disrupt the field of 3D printing by providing access to materials with advanced properties, including on-demand editing of surface and bulk properties, self-healing, and control over nanostructuration and mechanical properties. This mini-review analyzes the development of photoRDRP techniques in the field of photoinduced 3D printing with an emphasis on the advanced and highly tailorable materials possible through these techniques.