In article , Qingpei Hu says...

Hi, Dear All,

I have alwaying been thinking to make a light, tiny, paper(or some
other light material) butterfly, that could fly with flapping his
wings by some mechanical power engine(like clockwork spring or elasic,
or else).

Neon
My son and I fly very delicate Indoor model airplanes and one of the classes he
flys is ornithopter. If you go to my son's web page you can see some styles of
these models including a rubber powered ornithopter with which he has won many
contests and also has set records. hope this helps.

http://www.indoorfreeflight.com/

See ya

Chuck S