Dragonfly Science

thingiverse

###We have successfully completed the prototype of a mechanical radio control dragonfly and are now raising funds to bring it to market through our KickStarter campaign. This campaign will allow you to purchase the Dragonfly RC or invest in our company GadgetANNI. Details on how to own a part of GadgetANNI will be posted shortly. If you have questions, please message me through your Thingiverse account. One of the most fascinating creatures on Earth, the dragonfly has a very ancient and unique flight pattern. Unlike airplanes, which use aerodynamic lift to carry their weight, the dragonfly uses a lot of aerodynamic drag to stay aloft. What's odd is that with airplanes you always think about minimizing drag, but in the case of the dragonfly, drag is used to create lift. The physics of dragonfly flight inspired me to build a mechanical dragonfly based on scientific research by Z. Jane Wang and Akira Azuma. This design utilizes drag to create flight by using theoretical models including momentum theory and the blade element theory. The inspiration for this mechanical insect originated from many of the fantastical gadgets of Leonardo da Vinci and other mechanical creations once thought futuristic in times long past. ###The Wings The design of the wings was crucial in figuring out how to use drag to create flight. Dragonflies are insects belonging to the order Odonata, which have two pairs of similarly sized long thin membranous wings that move independently during flight. As the forewing lifts, the hindwing lowers, creating a distinctive phase relation between the wings during various maneuvers. Creating oscillating wings at a specific distance apart develops whirls on top of opposing wings, which creates lift. Wings had to be close enough for them to interact hydrodynamically. ###The Engine The engine that flaps the wings is driven by a twisted rubber band that turns a crank shaft. Mimicking nature's design while maintaining a simple design was a challenge, so we defaulted to a proven design. The reason for this decision was influenced by the nature of how a dragonfly uses its muscle. A dragonfly's muscles flap its wings by flowing blood in its veins, which manifests Coriolis forces. When muscles attached to the dorsal surface of the thorax contract, they pull down on the tergum, drawing the wing bases down and causing the wings to lift up. ###Wing Movement The flapping rate of the wings maintains the forces that keep the dragonfly airborne. We compromised the wing speed from 30 beats per second to 2 beats per second and added a gliding feature to the design. Dragonflies are also good gliders, with some larger species able to glide for 20 m at an angle of 10 degrees. Dragonflies flap and pitch their wings at a rate of about 40 Hz, and the blood flowing in veins induces Coriolis forces in the flapping wings. ###The Body Design When art and science merge, the result often becomes an elaboration on scientific data through a more artistic medium. The most sturdy and elegant design for the body was to use a "X" shape along the tail and underbelly. This sturdiness allows for greater pressure from the twisting of the rubber band. https://youtu.be/r8CszYNxGHg