The Casimir Effect—the attractive force between uncharged conductive plates in a vacuum—is a macroscopic manifestation of zero-point energy. In Micro- and Nano-Electro-Mechanical Systems (MEMS/NEMS), this force is a primary failure mode (stiction). Standard Quantum Electrodynamics (QED) calculates this force by summing the modes of the electromagnetic vacuum under boundary conditions. Unified Field Dynamics (UFD) offers a complementary Elastic-Geometric derivation. We model the Casimir force as the Elastic Tension of the unified vacuum field q confined between material boundaries. Unlike standard QED, which treats the vacuum as a passive mode reservoir, UFD treats it as a physical medium with finite stiffness (1/G) and bending rigidity (alpha). We demonstrate that the Casimir energy density is modified by the Local Curvature of the boundaries. While recovering the standard Casimir law (F ~ 1/d^4) for infinite flat plates, UFD predicts significant deviations for nanostructured surfaces with high curvature (e.g., corrugated or fractal geometries). Specifically, we derive a Geometric Correction Factor that depends on the ratio of the vacuum coherence length to the surface radius of curvature. This suggests a novel pathway for "Vacuum Engineering": by patterning surfaces with specific topological textures, the sign of the vacuum tension can be modulated or even reversed (repulsive Casimir effect), offering a passive solution to stiction in next-generation nanodevices.