Multimaterial additive manufacturing through grayscale digital light processing 3D printing

Grayscale digital light processing (g-DLP) has emerged as a significant advancement in multimaterial additive manufacturing, providing high precision and versatility in the fabrication of complex, multifunctional structures. By modulating ultraviolet (UV) light intensity at the pixel level, g-DLP enables spatially resolved tuning of mechanical, optical, and electrical properties within a single part using a single resin vat. This approach addresses the traditional limitations of digital light processing (DLP), such as a single set of material properties, while preserving the key features of high resolution, smooth surface quality, and efficient layer-by-layer fabrication. This perspective paper introduces the foundational mechanisms and key technological breakthroughs that have positioned g-DLP as a multimaterial manufacturing technique. A diverse array of applications is discussed, including the fabrication of integrated fiber and matrix composites to achieve enhanced mechanical performance, the precise modulation of optical properties, multicolor printing from a single resin vat, the development of functional electronic components with tailored conductivity, and 4D printing for dynamic, stimuli-responsive systems. By leveraging pixel-level control of material properties, g-DLP not only broadens the scope of design possibilities but also delivers a combination of efficiency, customization, and multifunctionality. It enables the creation of advanced materials and devices for next-generation applications.