One of the main questions is how the dynamics of the self-propelled Janus particles relates to the dynamics of the temporally modulated light field to achieve an efficient sieve performance. Therefore, first, fundamentals of the propulsion of thermophoretic swimmers in a static light gradient have to be explored. For example, it needs to be clarified which particle parameters (size, surface morphology or charge) are responsible for a pronounced difference in velocity and direction of the particles in the light gradient. Experimental parameters such as light gradient and width of the gradient, as well as a suitable temporal modulation of the light field will be adjusted. For the studies mainly dark field microscopy will be used.

In a later period of the subproject, a microgel will be attached to the Janus particle as cargo, which can have different functions, such as changing the fluid dynamics around the particle, and/or acting as a stimuli-sensitive container for smaller molecules, which can be carried over the barrier inside the microgel and released behind the barrier.