Blimps have no structure of any kind within the envelope, only helium and air.
All but one airship model seen flying today are non-rigid, and use a gas called helium, instead of wings, for lift. Using the advanced technology available today in materials and computer aided design, the modern airship seems a distant relative to those of only 50 years ago. The envelope, which when inflated is aerodynamically shaped and contains helium for lift, is a proprietary design made of modern synthetic materials. These are stronger than steel by weight, and impervious to ultraviolet light degradation, a problem with earlier envelope life. Helium gas is a natural fire extinguisher and, while once rare, is available world wide as a byproduct of natural gas production.