Kim, I don't know if this could help, but I used to make great kites that
looked like wings from thinnish dowel rods, duct tape and dark garbage bags.
The bags stretch just enough and the dowels bend just enough to get good
tension across the top. You might could find darker tape than the silver. We
left the bottom edge loose to cut like bat wings. (summer arts program)
If you take a look at some "jumping jack" plans (the little toys that move
when you pull the string) you might get an idea how they could have one
string to pull in the front to move the wings up and down. Basically, it is
one point at the bottom to rotate, and another higher point to run the
thread through, around to the front, to pull.