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Campus Functional materials and structures®
Der Clausthaler Campus im Grünen als Luftaufnahme

Functional materials and structures

In materials science, it is common to classify materials into structural materials and functional materials. Structural materials are non-active materials that are used primarily for their outstanding mechanical properties (strength, stiffness, density, hardness, etc.). The classic example of this is steel. In contrast, functional materials possess properties that enable energy conversion within the material based on specific physical effects. They can be used directly as active transducers, or their properties can be specifically and reversibly modified. Functional materials do not belong to any single material group.

Examples of functional materials include:

  • piezoelectric materials
    (e.g., ZnO, BaTiO₃, PVDF, KTN, KNN)
  • optomechanically active materials
    (such as LiNbO₃, KTN, ZnO, SBN, azo polymers)
  • shape-memory materials
    (e.g., NiTi, ZrO₂, AuCd, CuZnAl)
  • electroactive polymers (e.g., CNT), or
  • Electro- and magnetostrictive
    materials (PMN, Terfenol-D, Fe₃O₄).

The phenomenon of material functionalization is evident in both structural and functional materials as soon as a specific structural modification is applied to the component or its surface; for example, the ability to adhere to a smooth surface through the generation of hexagonal nanobricks. The campus has therefore placed functional structures at the center of its research alongside functional materials and incorporates this focus into its name.

Functional structures are materials with specialized structural features that impart functionality beyond their original mechanical purpose. Functional structures are used to endow components with new properties. Their potential for multifunctional use is particularly great when they are made of functional materials. Such functional structures can then be understood as highly advanced specialty materials with a high degree of functionality.

Examples of functional structures include:

  • CNT fibers
  • vibration-isolating double-helix springs for mounting mirror surfaces in automotive mirrors
  • piezoelectric actuators in a honeycomb shape
  • Nanocolumns and helical membranes made of piezoelectric zinc oxide
  • piezoelectric nanocomposites
  • Bio-inspired and self-organizing or potential-based construction methods