Baby Beetles Inspire Pitt Researchers to Build “Mini Boat” Powered by Surface Tension
Propulsion technique harnesses natural pull of water’s surface, similar to how beetle larvae move through water
Inspired by the
aquatic wriggling of beetle larvae, a University of Pittsburgh research team
has designed a propulsion system that strips away paddles, sails, and motors
and harnesses the energy within the water’s surface. The technique destabilizes
the surface tension surrounding the object with an electric pulse and causes
the craft to move via the surface’s natural pull. The researchers will present
their findings Jan. 26 at the Institute of Electrical and Electronics
Engineers’ 2009 Micro Electro Mechanical Systems (MEMS) conference in Sorrento,
Italy.
This method of propulsion would be an efficient and low-maintenance mechanism
for small robots and boats that monitor water quality in oceans, reservoirs,
and other bodies of water, said Sung Kwon Cho, senior researcher and a
professor of mechanical engineering and materials science in Pitt’s Swanson
School of Engineering. These devices are typically propeller-driven. The Pitt
system has no moving parts and the low-energy electrode that emits the pulse
could be powered by batteries, radio waves, or solar power, Cho added.
Cho envisioned the system after reading about the way beetle larvae move on
water, he said. Like any floating object, larva resting in the water causes the
surface tension to pull equally on both sides. To move forward, the larva bends
its back downward to change the tension direction behind it. The forward
tension then pulls the larva through the water.
Cho and his team—Pitt engineering doctoral students Sang Kug Chung and Kyungjoo
Ryu—substituted the larva’s back bending with an electric pulse. In their
experiments, an electrode attached to a 2-centimeter-long “mini-boat” emitted a
surge that changed the rear surface tension direction and propelled the boat at
roughly 4 millimeters per second. A second electrode attached to the boat’s
front side served as the rudder.
There is always newsworthy research and events happening in the Swanson School of Engineering.
You are using a browser that does not support current Web standards. Although this site is viewable in all browsers, it will look much better in a browser that supports web standards.
