The ability to reversibly modulate macroscopic surface properties is an important requirement for numerous biomedical applications, such as cell culture, tissue engineering, biosensors, biofouling and microfluidics. While dynamic remodeling of materials and interfaces is a widely observed phenomenon in nature, examples of synthetic systems that can be switched on-demand are scarce. Recently, numerous active model systems have emerged, which rely on conformational transitions in molecularly defined films driven by external stimuli. In this article, we review recent advances in stimuli-responsive materials specifically focusing on monolayers formed by molecules such as peptides and oligonucleotides and their applications in biotechnology.