Washington, June 22 : Mechanical engineers have identified a biological mechanism in young mayflies that could be duplicated in tiny robotic devices to enable sensors in stagnant environments to make air or water flow past them so they can detect harmful substances.
The discovery was made by mechanical engineers Ken Kiger and Elias Balaras, of the A. James Clark School of Engineering, and entomologist Jeffrey Shultz, College of Chemical and Life Sciences.
Young aquatic mayflies, or "nymphs," enhance their respiration using gills, creating a flow of fresh water with the help of seven pairs of nearby gill plates that flap like a Venetian blind.
The flow of fresh water is generated by the plate's motion, directing water to the mayfly's gills as efficiently as possible.
"By duplicating the action of the mayfly gill plates in a tiny robotic device, we hope to create a flow of air or water to sensors in stagnant environments, so they can operate more effectively," said Kiger.
The researchers are exploring how the mayfly's gill plates work, and how to make a robotic version, working on duplicating and measuring the gill plate movement in a virtual computer model.
Once the mayfly grows to a certain size though, it is capable of creating an inertial effect, or ripples, of its own. Its gills respond accordingly, which is a trait the researchers hope to replicate in their sensors.
"Mayfly sizes are right at the point where issues of viscosity and inertia switch in importance," said Kiger. "Depending on whether the weight or the thickness of the water is influencing its movement, the mayfly switches the way it pumps water to its gills," he added.
The current trend in sensor technology is to strive for smaller and more compact devices to enhance their portability and reduce power consumption.
As a result of this trend, traditional technology sensors will run into the same difficulty as experienced by the mayfly as the sensors reach smaller and smaller sizes: eventually a transition will occur where inertial flow mechanisms will become ineffective.
But, studying how the mayfly deals with this transition can give scientists insight into how to better develop equivalent engineered sensors.
The next step for scientists will be to construct a tiny artificial micro-robot that can reproduce the switchable gill action of the mayfly nymph.
Such a mechanism could be installed in sensors intended to detect unhealthy air in otherwise stagnant areas, such as in subway stations or mines.
If a miniature set of robotic mayfly gill plates can move air over a sensor, potentially harmful substances can be detected faster.