Lipid droplets (LDs) were believed many years ago to be mere passive reservoirs of lipids, which role was limited to supply lipids to cell membranes when needed and to avoid the accumulation of fat in adipocytes leading obesity. Since this last decade a newly focus on LDs has led to understand their dynamic organelles behavior and their implication in many diseases proliferation in cells. Indeed, the virus or proteins linked to them are located on LDs and therefore the understanding of the biogenesis of lipid droplets (by budding from a membrane) and their pathway (fusion between LDs) became of great interest. Unfortunately, a little is understood about that but many Biology labs start now to converge on the topic. However, all the approaches proposed to study the budding and fusion of LDs are done in in vivo systems mostly by knocking down or over expressing a list of proteins, presumable responsible of the effect, and watch the consequences. We think it doesn’t guarantee their direct implication and there is additionally a lack of a clear visualization of the processes and their energy characterization. We propose to use emulsion droplets based on microfluidics so study them. COPI (GTP, Arf1 and coatomers proteins) which is involved in the budding of vesicles is likely implicated in the budding of LDs. To prove that, we will form water drops in an oil containing phospholipids that will cover their interface. The water drops will contain the COPI; oil droplets will be therefore budded from the phospholipid monolayer at the interface: we have preliminary results confirming that. Regarding the fusion process, the way SNARE proteins assembly (v and t-SNAREs) leads to fuse vesicles is believed to provoke the merge of LDs. We will investigate that by forming in microfluidics oil drops decorated separately with t and v-SNAREs that will be approached together by using the micropipette technique and fusion events will be watched.