Contact-free Mechanical Manipulation of Biological Materials

In biotechnology and medicine, controlled studies on biological material are fundamental for developing new methodologies and therapeutic approaches. To explore the nature of biological processes and to test inherent material properties, it has become increasingly clear that new experimental methods must be developed in order to allow precise manipulations and quantification of biological materials on the microscopic level. Traditional methods often rely on physical contact with the sample, which can induce drastic artifacts in soft biological systems. To bypass this limitation, tools for contact-free manipulation were developed, which even enable the induction of whole-cell deformations to explore their mechanical properties. These approaches facilitate extensive investigations of single molecules, molecular ensembles, cells and even tissues, potentially reducing the need for animal studies. In this rapidly changing field, it is nearly impossible to provide a comprehensive overview of all available techniques since new methods are constantly being developed. In this chapter, we highlight many of the predominant approaches, aiming to investigate cellular as well as subcellular mechanical properties and processes.