07: NESTED DOLL
Nested Doll is the practice of saving space and enabling movement by placing one object inside another (like Matryoshka dolls) or enabling parts to retract inside each other—this reduces the system footprint, enables portability, and allows for telescopic action or deployment.
This principle is expressed in three common moves:
Place one object inside another; place each object, in turn, inside the other (e.g., nesting containers, storage)
Make one part pass through a cavity in another (e.g., telescoping structures, sliding mechanisms)
Make parts capable of folding, stacking, or collapsing inside each other (compact designs for storage/transport)

Why "Nested Doll" creates innovation?
When you use nesting and telescoping, you unlock several critical design advantages: