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I you're talking about removing hard-to-get tree branches that you can't re ach, then a remote-controlled might be good, but mechanically actuated cutt ing is still like all of the rest of the cromagnon talk you see about just TOTALLY out-of-date stuff, here.
Instead of using a chain saw, you might be able to use something called a M ASER which emits a concentrated beam of microwave energy. So its different from a laser which emits a highly concentrated beam of light that can help with cutting, joining, fashioning, etc...