40: COMPOSITE MATERIALS
Composite Materials is the practice of combining two or more materials with different properties into a single system so you get the "best of both"—strength where needed, light weight where possible, durability at contact zones, and specialized functions (insulation, damping, corrosion resistance) without excess. You replace thin/heavy single-material parts with a 'smart' material structure that improves performance, minimizes thickness, or hybrid structure without performance/energy for loss from mass.
This principle is expressed in three common moves:
Replace a uniform (single-material) object with a composite (two or more materials working together);
Combine materials with complementary properties (e.g., strong/light, hard/tough, conductive/insulating) to satisfy contradictory requirements;
Use layered, fibrous, honeycomb, or matrix-form configurations/fiber reinforcement, honeycomb cores, multi-layer coating to master performance by regions and direction;

Why "Composite Materials" create innovation?
When you combine materials deliberately, you unlock multiple advantages at once: