The ability of birds to fly more efficiently by changing the shape of their wings has inspired a number of approaches to developing low-energy aircraft. If this technique can be replicated, where individual feathers are adjusted to guide the animals through the air, it could make for vehicles that are lighter, faster and more maneuverable. With a view to making such shape-shifting wings a reality, scientists are about to get up close and personal with our avian friends, launching into the most detailed analysis of bird flight ever conducted in the name of aerospace engineering.

Turning to nature to advance aviation is hardly a new endeavour, indeed the Wright brothers themselves studied birds to get the field off the ground in the first place. Today's researchers are no different. Daniel Inman, professor of aerospace engineering at the University of Michigan, is heading up an international team of researchers in an effort to transplant the shape-shifting nature of birds' wings to modern fixed-wing aircraft, which currently use flaps and slats for control.

"With new materials, advanced sensing and control techniques, and inventive methods for observing birds in flight, our team will begin to bring avian efficiency and agility to aircraft," Inman says.

With a US$6 million grant tucked under his arm, Inman and his team will put flapping wings under the microscope in an unprecedented way. Part of this involves a new system developed at Stanford University that measures pressure disturbances in the air around the bird, a less invasive approach than loading the animals up with various sensors to track airflow and pressure.

"It is really exciting that we can now finally study bird flight with an engineering eye," says David Lentink, the assistant professor of mechanical engineering at Stanford who developed the system. "The time-resolved forces on the wings, in combination with 3D wing shape measurements at 1,000 frames per second, are key to deciphering how birds change shape to control the aerodynamic force they generate."

Meanwhile, biologists will attach cameras to large species like eagles to get a close-up view of their wings as they take off, glide, maneuver and then land, while another group will investigate the way wing muscles work together to change the shape of the wing.

This model of an airplane wing changes its shape using materials that react to an electrical current(Credit: Joseph Xu, Michigan Engineering Communications & Marketing)

But the biomimicry doesn't stop there. The engineers will also look to develop a control computer that works in a similar way to a bird's brain during flight. This central computer will receive information from sensors integrated throughout the wings that act like nerves, relaying data on airflow and pressure. The hope is that this system will be able to select ideal wing shapes on the fly.

The researchers will also be testing out materials that can change shape when encountering certain stimuli, like temperature changes or electrical currents, and say that building structures resembling the bone and muscle of a bird's wings will be possible with 3D printing.

Initially, the team has set its sights on boosting the efficiency of battery-powered unmanned aircraft. However, it will also investigate whether the components the develop can eventually find a home on smaller crewed aircraft as well.

You can hear from Inman in the video below.

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