Mikroplavalci na osnovi marangonijevega pojava

Članek je sestavljen iz dveh delov. V prvem delu bodo predstavljeni površinski pojavi pri kapljevinah, ki pripeljejo do Marangonijevega pojava. Najprej se spozna površinsko napetost, ki je gonilna sila tega pojava, in napetostni tenzor v tekočinah, vpeljava katerega omogoča izpeljavo robnih pogojev na površini tekočine. V nadaljevanju se izpelje pogoje za statično ravnovesje na površini in kdaj pride do dinamike. V drugem delu je obravnavana samo-premikajoča kapljica emulzije. Do premikanja pride zaradi nastanka Marangonijevih tokov na meji kapljica - zunanja tekočina, ki so posledica nehomogenosti površinske napetosti kapljice. Izračuna se hitrostno polje po vsem prostoru, tako znotraj, zunaj kot tudi na površini kapljice in določi hitrost premikanja kapljice. Za konec sta predstavljena dva načina vzpostavitve nehomogenega profila površinske napetosti ter preučena njuna mehanizema.

Microswimmers driven by marangoni effect

Article consists of two parts. In first part of the article surface phenomena in liquids are presented, which results in Marangoni effect. First of all surface tension, which is the engine of this phenomenon, and stress tensor in liquids are introduced, introduction of which enables derivation of boudary conditions on liquid surface. Conditions for static equilibrium on surface are analyzed and when dynamics comes into play. In second part of the article self-propelling emulsion droplet is analyzed. Movement is consequence of induced Marangoni flow on border between droplet and outside fluid, which is the result of nonhomogenious surface tension of droplet. Velocity field is calculated, inside, outside and on surface of droplet, also velocity of our droplet is determined. In the end two possible ways to establish nonhomogenious profile of surface tension are presented and mechanism behind it is analyzed.