• Physics-based, numerically solved models for injection and reaction injection molding emerged, coupling non-isothermal flow, curing kinetics, and pressure evolution to predict fill length, packing, and stability. Finite difference/finite element discretizations and sensitivity analyses anchored process design [3], [7], [10], [12], [13].

• Process–structure–property mapping in thermoplastics emphasized how flow and thermal histories imprint orientation, residual stresses, and crystallinity, using birefringence, density, and X-ray to link molding conditions (gate, runner, jetting) to part performance; die-induced fiber alignment extended this logic to short fiber extrudates [5], [6], [17], [19].

• Deposition and direct-write manufacturing consolidated as a cross-domain paradigm: continuous vapor-phase axial deposition for optical preforms, drop-on-demand ink jet for patterned materials, and near-net-shape 3D printing for metals all highlight layerwise or continuous additive routes enabling customization and rapid iteration [1], [4], [15], [20].

• Biofabrication matured from concept to ecosystem: commercial bioprinters, standardized bioinks, and application-specific constructs (hybrid retina, modular bone scaffolds, printed microfluidic assays) framed 3D bioprinting as a platform for tissue models and diagnostics rather than a single technique [9], [11], [16], [18].

• Materials formulation and rheology engineering became central to printability and fidelity across modalities, from hydrocolloid-tuned food inks to reactive viscosity/gelation control in reaction molding and jetting inks, tying chemistry and flow to shape retention, resolution, and cure [2], [3], [13], [15].