Transformative Materials Research: Defining Conceptual Change across Scales.

What qualifies as transformative materials research? In this Viewpoint, we use "transformative" to denote work that forces revision of underlying assumptions, enables generalization across systems, or reveals regimes inaccessible to existing frameworks. The term is widely invoked yet rarely defined with disciplinary precision. Perspectives spanning nanomaterials chemistry, catalysis, soft and bioinspired interfaces, and functional materials suggest that transformation occurs when new reaction mechanisms are uncovered, when structure-property relationships are redefined, and when operation under realistic chemical environments reveals fundamentally new governing mechanisms. Foundational insight, developmental refinement, and industrial realization constitute an interdependent value chain through which transformative discoveries mature into societal impact. Mistaking progress within a single component for a fundamental shift risks blurring the line between incremental refinement and genuine conceptual change. Transformation requires a conceptual discontinuity in at least one stage of this value chain, most commonly through foundational scientific insight, while the remaining stages enable its realization and broader impact. This Viewpoint argues that transformative materials research is defined less by topic than by intellectual pursuit, chemical and structural rigor, and sustained engagement with unexpected observations during mechanism discovery and eventual validation under realistic chemical environments and at scale.