Unicellular Organisms with Versatile Solutions at the Micro-Scale: Functional Materials and Principles in Ciliates

Nature's diversity offers an abundance of promising solutions for novel bioinspired functional materials and systems. In particular, single-celled organisms exhibit solutions and material properties that are realized at the nano- and micro-scales. Ciliates are ubiquitous unicellular eukaryotes that are well-adapted to a wide range of environmental conditions. They have developed a large variety of interesting and highly specialized characteristics with unique properties and design. In this review, the background of selected ciliate characteristics is highlighted with respect to material properties and structure-function relationships. Hierarchically complex mineralized structures, highly efficient sensors for movement and protection, shape-memory structures, as well as survival and detoxification strategies are to be emphasized. Proposed future bioinspired applications of these properties of ciliates expand the possibilities to more sustainable materials and development processes. Considering functional and structural materials and systems inspired by the principles of living nature, single-celled organisms in particular are a promising model. The amazing bandwidth of different materials in ciliates ranges from nanostructured composites, over mineralized structures to self-assembled protein structures. This review gives an overview of the background and recent progress in this field of research.image