There were many confusions before I watch this video.. Thank you.. Please upload other videos as well that includes sputtering method for electrodes and other methods as well...
instead of patterning the negative, is there a reason not to have patterned the channels, and etched the negative into the substrate, removed the mask, and then used solid silicon as a more durable mold? perhaps coating it with PTFE (which i believe can be sputtered) for a mold that i suspect (i guess i don't really know) might have a longer lifespan?
it depends on how good your etch is. most people just use su8 because its rapid way of fabrication for prototyping. if you are 100% sure that you will perpetually use the same mold over and over again then you can eventually etch down a wafer but then you will have to ensure that the quality of your etch is good enough that you can can PDMS on top of it reliably. With either a wet or dry etching step you will introduce the chance of perhaps an anisotropic etch for example with other factors such as roughness that a well developed photoresist might not have.
