Virginia Tech Mechanical Engineering Annual Report 2019 Annual Report | Page 8

Sea urchins provide clue to light materials In the search for strong, lightweight materials, researchers are looking to sea urchins, which have spines made of chalk, a generally brittle substance. Ling Li Assistant Professor Research Focus: Biological structural materials; Bio- inspired materi- als The complex three-dimensional struc- ture of sea urchin spines that is 70 to 80 percent porous creates a stable and strong structure. Studying the sea urchin is part of a $540,000 National Science Foundation grant being inves- tigated by Ling Li. By using design rules gathered from studying biological systems and input- ting those rules into the design of bio- inspired lightweight ceramic materials, Li said he hopes the information can be applied to creating lightweight pan- els and other components. Diseases spread by ‘sneezing’ plants In an article published on the cover of the Journal of the Royal Society Interface, Virginia Tech researchers have found that wheat plants ‘sneezing’ off condensation can vastly impact the spread of spore-borne diseases such as wheat leaf rust which can cause yield losses of up to 20 percent or more in the United States, and higher losses in less developed agricultural na- tions. The study is part of a three-year grant from the US Department of Agriculture’s National Institute of Food and Agriculture to study the dispersal of wheat pathogens by rain splash and jumping-droplet condensation. Jonathan Boreyko, assistant professor of mechanical engineer- ing is a co-PI on the nearly $500,000 project. “Conceptually, what the plants are doing is sneezing,” Boreyko said. “The jumping droplets, at the rate of 100 or more an hour, are a violent expulsion of dew from the surface. It’s good for the plant because it is removing spores from itself, but it’s bad because, like a human sneeze, the liquid droplets are finding their way onto neighboring plants. Like a cold, it’s easy to see how a single infected plant could propagate a disease across an entire crop.” 8 Revised and Corrected, Nov. 2019 Jonathan Boreyko Assistant Professor Research Focus: Interfacial fluid mechanics; Biomimetic engineering; Water and energy harvest- ing; Droplet dynamics; Syn- thetic trees