Biomimetics: A Snake in Darwin's Garden
Casey wrote here recently:
If natural structures outperform our best technology, what does that say about the origins of those structures in the first place? While this does not provide an absolute knockdown argument for intelligent design, you can hardly deny the ID-friendly implications of a design approach that looks to natural structures as an ideal template for human technology.Offering the latest illustration of biomimetics -- the science of taking design tips from supposedly undesigned features of various organisms -- mechanical engineering grad student Hamid Marvi at the George Institute of Technology has won some notice. He wants to build a robot that can help find and rescue survivors of disasters from otherwise inaccessible rubble. The challenge is discovering a way to send such a device slithering effectively up or down treacherous surfaces.
That's where snakes come in, as Inside Science notes:
Marvi and his colleagues have designed snake-inspired robots by studying live snakes. Snakes cannot move without friction. When snakes are placed on a very smooth surface, with little friction, they slither wildly but cannot get anywhere.Marvi has made a video of Scalybot available, which you can see here.
"Snakes can generate waves but they cannot move forward [in the absence of friction]," Marvi said. Instead, snakes rely on friction to move. Sliding against surfaces, snakes' bodies create friction in different directions -- less friction towards the front of the body than towards the back of the body in order to move forward.
Snakes use friction even when they are sleeping -- which is handy for preventing themselves from falling if you try to tilt them on a plane. The texture of their scales, and the way that the scales are arranged -- which can resemble venetian blinds on top of each other -- create this passive friction.
When they are awake, snakes generate at least twice as much friction, Marvi said, demonstrating that they consciously use friction to their advantage in navigating environments.
Snakes actively adjust their friction, Marvi explained, by modifying the relative angle between their scales and the surface, to adjust the levels of friction according to their needs.
Marvi and his colleagues adopted these principles to create Scalybot, an artificial robot designed to climb inclined planes. Scalybot contains scale-like teeth along the bottom of its body, and these teeth can raise or lower depending on what it needs to do to navigate the environment.
Photo credit: Iguanasan/Flickr.