Hi to all the forum members, my questions for this tread are correlated to the robotics arms for wafers like the robotics arms that are in this website: www.kensingtonlabs.com 1. why is so important to build very very accuracy robotics arms, Wafer Handling Systems , in the machines of semiconductors industry that arrive to 1 micro meter accuracy? in other words why the semiconductors industries invest a lot of money in research and development of very very accuracy robotics arms? and how it will make the chips for the CPU of the computers or smartphones better? 2. If the wafer that the robotics arm move was have 300 millimeters diameter and now the wafer diameter enlarge to 450 millimeters so the wafer became to be heavier and bigger so what need to change in the robotics arm for wafers with 300 millimeters diameters that it will continue to be very very accuracy also for wafers with 450 millimeters diameter? I think, but I am not sure, maybe the answer can be correlated also to very very accuracy machines productions or Hard Disk Drivers that are also very very accuracy. I also will be happy to receive from the forum members links to article websites or relevant books like from google books or relevant lectures like from youtube education that are correlated to these questions, thank you.