Leaf-inspired energy device could power tech on Mars

Developed at Warwick University, the energy harvester came about off the back of an annual challenge given to engineering students where they had to figure out why aspen leaves quiver in even the slightest breeze. After setting the undergraduates the task for several years, researchers Sam Tucker Harvey, Dr Igor Khovanov and Dr Petr Denissenko decided to investigate if the unique phenomenon behind the leaf movement could be used to harness energy.
Read more here: https://www.theengineer.co.uk/energy-harvesting-device-aspen/ 
or access the APL article here: 
Appl. Phys. Lett. 114, 104103 (2019); https://doi.org/10.1063/1.5083103

Abstract
Aeroelastic energy harvesters are a promising technology for powering wireless sensors and microelectromechanical systems. In this letter, we present a harvester inspired by the trembling of aspen leaves in barely noticeable winds. The galloping energy harvester, a curved blade oriented perpendicular to the flow, is capable of producing self-sustained oscillations at uncharacteristically low wind speeds. The dynamics of the harvesting system are studied experimentally and compared to a lumped parameter model. Numerical simulations quantitatively describe the experimentally observed dynamic behaviour. Flow visualisation is performed to investigate the patterns generated by the device. Dissimilar to many other galloping harvester designs, the flow is found to be attached at the rear surface of the blade when the blade is close to its zero displacement position, hence acting more closely to aerofoils rather than to conventionally used bluff bodies. Simulations of the device combined with a piezoelectric harvesting mechanism predict higher power output than that of a device with the square prism.