How can a humpback whale and a device that works on the same principle as the clicker that starts your gas grill help an unmanned aerial vehicle (UAV) fly longer and with more stability?
Well, it all starts with biological structures called tubercles that the whale uses for its unique maneuvers in the ocean. Felix Ewere, a doctoral student at The University of Alabama in Huntsville (UAH), made a mechanical version of the wavy-looking biological structures and attached it to a piezoelectric energy harvester.
Michael Mercier / UAH
Felix Ewere, left, and Dr. Gang Wang near a wind tunnel they use for testing in UAH’s Olin B. King Technology Hall. Inside the tunnel is their latest miniaturization effort, while Ewere holds the intermediate effort and Dr. Wang holds the initial device constructed.
The piezoelectric principles the harvester uses convert mechanical action into electricity just like the red piezoelectric button on your gas grill does.
Humpback whales have rounded tubercles located on the leading edge of their fins.
“For anything under the action of fluid, two forces are created – a lift force and a drag force,” Ewere says. “For the humpback whale, these tubercles increase the lift and reduce the drag as it moves through the water. They are what enables it to breech the surface of the water.”
Borrowing from the whales, the new device is used to harvest energy and can be employed as an airflow or fluid speed and direction-sensing device. So UAV designers can use the “galloping piezoelectric” principle to design better craft by placing sensor piezoelectric devices all over their models to test them to determine how they behave in the fluid currents of air. Plus, they can attach the devices to the UAV as harvesters to generate power to extend its battery range.
Ewere has a bachelor’s in mechanical engineering and a master’s in aerospace engineering, and for his doctorate he joined his fluid physics experience to the piezoelectric expertise of his doctoral advisor, assistant professor of mechanical and aerospace engineering Dr. Gang Wang.
“He actually introduced me to piezoelectrics,” Ewere says.
The initial problem was to determine whether greater efficiency using wind could be attained so that the piezoelectrics could better harvest energy. Dr. Wang says he presented the problem, but Ewere is the one who came up with an interesting solution that ultimately took the pair in another direction.
“I just threw the question to him, and he found the answer for me, which is using this biologically inspired concept,” Dr. Wang says. “One day, he just knocked on my door and said, ‘Dr. Wang I want to try this one.’ ”
Next came wind tunnel experiments.
“We were trying to get more force and induce more strain by using this idea” to improve energy harvesting ability, Ewere says. It turned out that efficiency wasn’t increased but the pair discovered through experimentation that the devices could serve as a form of passive control. That makes them useful as measuring devices for air flow speed and direction.
“This is a new kind of flow sensor,” Ewere says. “A regular flow sensor will just tell you the magnitude of the wind, but this also shows you the direction.”
Work has progressed on miniaturizing the components to widen applications. Placing the sensors arrays on a helicopter, for example, could help engineers determine aerodynamics that could improve low speed and low altitude flight stability or reduce its acoustic signature.
Its energy harvesting capabilities are also being explored for use to charge the batteries that power small devices to track bird populations, extending their research life.
Now the theoretical work and design concept phases are drawing to a close and Dr. Wang is looking for applications funding.
“For three or four years now, we have been drawing up the basics of this, and we have done the basic research,” Dr. Wang says. “Now I have the tangible benefits for it, but to take it to the next level I need a boost from an interested funding agency.”
Jim Steele | newswise
How does the loss of species alter ecosystems?
18.05.2017 | Deutsches Zentrum für integrative Biodiversitätsforschung (iDiv) Halle-Jena-Leipzig
Excess diesel emissions bring global health & environmental impacts
16.05.2017 | International Institute for Applied Systems Analysis (IIASA)
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy