Applications of soft biomaterials based on organic and hybrid thin films deposited from the vapor phase

Soft biomaterials are a crucial component in several application fields. They are used, for example, in biomedical implants, biosensors, drug delivery systems as well as in tissue engineering. In parallel to extensive ongoing efforts to synthesize new materials, the development of means to tailor the materials' surface properties and thus their interaction with the environment is an important field of research. This has led to the emergence of several surface modification techniques that enable the exploitation of biomaterials in a broader range of technologies. In particular, the use of functional thin films can enable a plethora of biomedical applications by combining advantageous bulk properties of the substrate (e.g. flexibility, lightweight, structural strength) with tailored surface properties of the thin film (e.g. enhancing/prevention of cell proliferation, controlled drug release). For some biomedical applications, thin films can also be the main functional components, e.g. in biosensors. The present review focuses on recent developments in the applications of soft biomaterials based on thin films deposited from the vapor phase. In the field of soft biomaterials, the possibility of depositing from the vapor phase—without the need for any solvents—offers the unprecedented benefit that no toxic leachables are included in the biomaterial. Further, due to the complete lack of solvents and chemicals overall being used in small quantities only, depositing thin films from the vapor phase can be a more sustainable choice than other techniques that are commonly used.