Figure 1.

The established structure–function principle in material science is that the microstructure determines the properties, such as the mechanical and fluid handling characteristics (a). For wound dressings, “function” encompasses the mechanical, fluid transport, and retention properties (altogether). The focus of the vast majority of the existing testing standards for wound dressings is on the properties and function of the tested dressing products, not their structure or microstructure. In a multilayer foam dressing, for example, each layer of the dressing has its own set of the above properties, and accordingly, the “function” of the whole dressing structure is determined by the contribution of each of the material components, for example, to the effective permeability of the dressing structure (b).