Here's my idea for flexible arms! The tube is from older pneumatic sets, which are harder to come by these days. I admit I haven't bought many new Legos for a while, but I know the pneumatic hose is all over brick link. But the hoses are made by Lego, for all you purists out there.
Arms. Made of Pneumatic Hose, just thread any wire through them and put a hand on the end. Sorry that the picture is fuzzy.