Selective infusion of spatially controlled domains via vat photopolymerization 3D-printing for chemically diverse multimaterial parts

Creating multimaterial objects through vat photopolymerization (VP) is challenging due to difficulty transitioning between liquid resins. Multiwavelength VP has emerged as a prominent approach for achieving multimaterial parts through VP; however, the material scope has historically been limited to combinations of organic photo-resins. To address this limitation, we have developed a method that we refer to as infusion multimaterial actinic spatial control additive manufacturing (iMASC-AM). This technique uses dual wavelength light projection to create distinct material regions within a single printed part that display disparate affinity toward infusion of dissolved materials. Herein, we demonstrate the versatility of iMASC-AM with the infusion of organic dyes, silicone resins, and metal salts for patterned optical, mechanical, and conductive properties, respectively. Notably, mild thermal post-processing after infusion was found to reduce silver salts, leading to patterned combinations of electrically conductive and insulating domains and allowing for fabrication of functional circuits from a single print. The iMASC-AM method enables the creation of a wide variety of chemically diverse multimaterial parts with materials properties combinations that are generally inaccessible through VP.