What Can Woodpeckers Teach Us About Shock Absorbers?

Woodpeckers bang their beaks into trees as many as 22 times per second. The bones of these birds may be spongy, but hunting for insects is hard work. With each bite into bark, a woodpecker subjects its brain to deceleration forces of 1200 g. That's 100 times the g-force that would give an NFL player a game-ending concussion. Woody Woodpecker may not be able to pass like Super Bowl MVP Aaron Rogers, but he could take a hit.

So how do woodpeckers withstand such powerful deceleration forces? That's what two researchers from the University of California at Berkeley, Sang-Hee Yoon and Sungmin Park, wanted to find out. Woodpeckers have spongy skulls and hard but elastic beaks. Yet their bone structure provides little room for the vibration-dampening fluid between their skulls and brains. Fortunately, a special structure called the hyloid layer helps.

Based upon their research, Yoon and Park designed a four-part shock absorber that embeds glass beads in a steel-encased aluminum cylinder. A rubber layer simulates a woodpecker's hyloid while an aluminum shell serves as the thin layer of fluid between a bird's skull and brain. To simulate the skull's sponginess, glass beads measuring 1-mm in diameter were selected and then closely packed. An electronic device that the researchers embedded in the beads proves that the shock absorber can enable contents to survive up to 60,000 g.

In addition to protecting electronic devices, this new shock absorber could be used to improve the helmets that military personnel, race cars drivers, and football players wear. What are some other potential applications for this technology?

Source: Pop Sci