Surface gradients are surfaces with chemical or physical properties that gradually change over a given distance. Gradients are, on the one hand, omnipresent in nature. Concentration gradients across membranes are central to energy generation in cells, and biomolecule gradients direct the haptotaxis of cells, for example, in axonal outgrowth. This means that biomimetic gradients allow us to gain a deeper insight into biological processes by mimicking the in vivo situation in the lab. On the other hand, gradients can be a valuable materials research tool since they allow for a high-throughput and cost-effective analysis of the influence of a wide range of parameters in the minimum amount of time.
In general, surface gradients can be created in two ways. Either the outermost surface layer of a substrate is gradually modified, for example by irradiation with an energetic beam or by chemical etching, or a surface coating, such as a self-assembled monolayer or a thin polymer film, is attached to the surface in a gradual manner.
At LSST we focus on the development of new methods to create surface-chemical and surface-morphology gradients, and on their application for the investigation of interfacial phenomena in the areas of materials science, biology, physics and chemistry.