vertical scientific poster base image, complex layered composition, ultra-macro photorealistic scientific visualization of a self-healing smart polymer. foreground: semi-translucent elastomer sheet with a diagonal microcrack, crack edges glowing warm orange from dynamic covalent bond recombination, tiny spherical sub-micron nano-repair units with soft cyan rim light migrating along visible entangled polymer chains and stitching the fissure, non-humanoid. midground: cutaway cross-section revealing layered polymer morphology, entangled chains, folded lamellae, repair units moving through microchannels, subtle stress-field contour lines near the crack tip. background: cold blue future laboratory with out-of-focus holographic molecular chain projections, volumetric light, floating empty translucent callout panels without text. strong micro-to-macro scale contrast, layered depth of field, cinematic lighting, clean negative space at top and bottom for typography, journal-cover quality, hyper-detailed, 8k