UCI materials scientist and engineer David Kisailus wants to help make the toughest and most crush-resistant synthetic substances for use in national defense, aerospace and automotive design, and sports equipment, to name a few applications. 

For inspiration, he turns to some highly resilient species in the animal kingdom. 

While on a visit to the renown entomology museum at UC Riverside, where they were working at the time, Kisailus and his team became fascinated with the diabolical ironclad beetle. After a few years of in-depth research, they published a study on the insect in the October 2020 edition of Nature.

This desert-dwelling critter, which can be found among trees and rocky landscapes in the Southwest, evolved to be terrestrial, or nonflying, with tanklike toughness.

The materials scientists zeroed in on its elytra, the upper back portion of its exoskeleton, just behind the head. Deployed as wing-shielding flaps on flying beetles, the two pieces of the structure are fused together on the ironclad in an arrangement similar to a jigsaw puzzle, giving the insect an extraordinary defense against pecking birds and biting rodents and lizards. 

Kisailus’ team also looked at the composite materials – mainly chitin and protein  that make up the beetle’s protective outer layer and figured out how to make synthetic, fiber-reinforced versions of them. The man-made substances were successfully tested as a new way to fuse aircraft segments together without traditional rivets and fasteners, which represent weak points in plane structure.

A cross section of the medial suture, where two halves of the diabolical ironclad beetle’s elytra meet, shows the puzzle piece configuration that’s among the keys to the insect’s incredible durability. Jesus Rivera / UCI
A cross section of the medial suture, where two halves of the diabolical ironclad beetle’s elytra meet, shows the puzzle piece configuration that’s among the keys to the insect’s incredible durability. 

For a study published in Nature Materials in August 2020, Kisailus, a professor in UCI’s Department of Materials Science and Engineering, and his research group focused on the mantis shrimp. This aquatic creature has a blunt appendage called a dactyl club for attacking prey and smashing rocks to use in constructing its undersea home. 

The investigators employed advanced microscopic techniques to examine the nanoscale architecture and components of the clubs surface layer, finding that its unique combination of materials enables it to withstand crushing forces without sacrificing stiffness. These qualities are much sought-after for use in cars, football helmets and body armor. 

Kisailus says that he and his fellow researchers try to pursue projects that harness biology, physics, mechanics and materials science for engineering applications. His multidisciplinary teams, formed with the sponsorship of the U.S. Air Force, have made a series of significant discoveries with the potential to help create more reliable aircraft, tougher body armor and sports equipment, and stronger vehicles –all benefiting humanity.

Addressing today’s grand challenges through collaborative research
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Since its founding in 1965, UCI has been built on an ethos of interdisciplinary collaboration. One of the earliest physical structures on the university’s Orange County campus was Ring Road, a paved pedestrian byway that connects the institution’s major schools. The path enables researchers in the Henry Samueli School of Engineering to take a short walk over to the School of Social Ecology to coalesce on new ways to mitigate climate change-induced flooding impacts on California’s marginalized communities – to name but one example.

Researchers-in-lab

Another might involve chemists from the School of Physical Sciences working with materials scientists in Engineering, artificial intelligence specialists in the Donald Bren School of Information & Computer Sciences and physicians in the School of Medicine to interact on new tissue-mimicking implants to treat a host of afflictions. Researchers from every part of UCI are working together to address the most pressing challenges facing humanity, from energy and the environment to lifesaving advances in biomedicine.