Worth blogging again, The Barbarian Group's Biomimetic Butterflies. Watching them move makes me want to cry every time!
"The Butterfly wings are made of laser cut, heavyweight drawing paper. After laser cutting, and some clean-up with an X-Acto knife, the wings are glued to a small piece of cotton to form a simple and delicate hinge. Using lightweight fabric keeps the overall look clean and creates a hinge with much less resistance than a more standard mechanical hinge. Each wing is fitted with two pairs of neodymium magnets by sandwiching the wing paper between each pair, making sure that the polarity on all magnets is consistent. To keep the Butterfly in place, we pin it to the mounting board with black insect mounting pins.
The wings are articulated by moving a large neodymium magnet oriented so that it has the opposite polarity of the magnets on the wings. For example if the magnets on the wings all have the south pole facing down, the large magnet will have south facing up. So when the large magnet is moved close to the wings, the magnets on the wings are repelled causing them to close. To move the magnet, it is mounted to a servo motor using a 2" plastic drum. The servo faces perpendicular to the central vertical axis of the Butterfly’s body. The magnet is mounted on the edge of the drum so rotating the servo causes the magnet to move away from the Butterfly, which in turn lessens its effect on the wing."
Also Magnetic Structure Prints