Multimaterial 3D Printing

Light-based additive manufacturing, particularly stereolithography and digital light processing, has revolutionized the rapid fabrication of complex three-dimensional architectures with unprecedented spatial resolution. However, a persistent challenge in the field remains the seamless integration of multiple materials with distinct chemical and mechanical properties within a single, continuous printing cycle.

In this presentation, we introduce our recent breakthroughs in multimaterial 3D printing strategies that overcome these limitations through spectrally controlled photopolymerization. At the core of this methodology is the design of advanced hybrid resin formulations capable of undergoing orthogonal reaction pathways, specifically radical and cationic polymerizations. By utilizing photoinitiating systems sensitive to distinct spectral windows, we demonstrate that the curing kinetics and pathways of these individual components can be selectively and independently triggered using different wavelengths of light. This wavelength-selective control allows for the on-demand spatial modulation of the polymer network during the printing process.

Consequently, this approach enables the direct fabrication of heterogeneous material domains that exhibit highly contrasting mechanical stiffness, swelling behavior, and surface chemistry, all fully integrated into a single, monolithic structure without weak interfaces. We will discuss the fundamental photopolymerization kinetics, formulation strategies, and the resulting physical properties of the printed structures. Ultimately, this spatial dose-field and spectral modulation platform offers a versatile and robust pathway for engineering bioinspired architectures, soft robotics, and advanced functional devices with highly localized, tunable functionalities.