A Versatile Photoresist Scaffolding for Tunable Material Property, High‐Contrast Tomographic Volumetric Additive Manufacturing

Volumetric additive manufacturing (VAM) has vast potential for simultaneous preparation of 3D parts but has been inherently limited by the implementation of materials designed for traditional vat polymerization. Such resins are highly nonoptimal due to gravitational settling, low reaction conversion contrast, and limited green part mechanics. Here, the rationally designed VAM materials platform, in the form of a tunable, degradable, and covalently‐crosslinked polyurethane scaffold, enables access to a broad library of low‐viscosity monomers corresponding ultimately to a range of thermomechanical properties. In combination with a radical inhibitor, this library of materials significantly advances the capabilities and applications of VAM, facilitating the transition from prototyping to manufacturing by significantly expanding the accessible range of thermomechanical properties. This approach achieves high conversion contrast, quantitatively characterized by an order‐of‐magnitude modulus differential between in‐part and out‐of‐part regions, utilizing the solid‐like scaffold to prevent settling even over the extended timescale necessitated by high inhibitor concentrations, and empowers green part moduli up to tens of MPa. Upon print completion, thioester degradation in the scaffold reveals the final printed part with minimal property deterioration and less than 4% change in part mass. Together, this degradable‐scaffold photoresist establishes a generalizable and versatile materials strategy for high‐contrast volumetric additive manufacturing.