Bats are some of the most dynamic fliers around. Unlike insects, with one joint at the base of the wing, or birds with three wing joints, bats have a stunning twenty-five joints. These joints allow bat wings to change in more precise shapes, making them more maneuverable and controlled. And researchers from Brown University have created a robot bat wing to observe how it functions.
So why is researching bat wings so important? Well, first of all conventional wing types and plane wings aren’t particularly efficient for micro air vehicles, which have large potential for going places that people can’t and observing factors of their natural environment more precisely.
Currently, the robot bat arm has not yet been integrated into a winged design; instead, it is being used to test and understand the aerodynamic forces that are involved in bat wing flight. By measuring forces on the wing as it’s in a wing tunnel and monitoring the power output of the servo motors, scientists can measure how much energy is required to execute wing movements.
Even though the robot wing isn’t a perfect model of an actual bat wing, it has already shown scientists valuable information about wing movement. For example, the existence of wing folding (bats and birds fold their wings on the upstroke) has been known for a long time, but using this model scientists discovered that wing folding actually increases net lift by 50%. Using the robot wing is important because they can test arbitrary factors that could not be tested on actual bats. One could not ask a bat to flap its wings more times in the same amount of time, but now scientists can observe the effects of wing frequency on lift.
Of course, the robot also demonstrated a lot of information about the structure of the wing. When the elbow broke because of the joint kept on getting stretched out, the scientists wrapped steel cable around the area, demonstrating the effects of ligaments in actual bat wings. Wing membranes would break at their leading edges, prompting reinforcement with elastic threads and emulating tendons.
This sort of knowledge and testing could be very helpful for creating vehicles with many joints and incredible versatility, and the knowledge gained from these experiments could give more insight into more flight mechanics and overall the science of biological aerodynamics.
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You may have heard the expression blind as a bat, but it couldn t be further from the truth. Bats can see extremely well, and they have a wing up on humans at night, when they hunt for insects. Bats use extremely precise echolocation to figure out how far away an insect is, the size of the insect, and the direction the insect is heading. They are so precise that they can avoid obstacles as small as a human hair.