
Chris Yakacki, professor of mechanical engineering at CU Denver, is known for more than just teaching courses on additive manufacturing in the College of Engineering, Computing, and Design, and inviting students to his Smart Materials and Biomechanics (SMAB) Lab. After years of research, development, and trial and error, Yakacki and his CU Denver startup, Impressio, became one of three teams awarded $1.55 million by the National Football League (NFL) to improve helmet safety for players across the nation.
Yakacki’s company, Impressio, was launched in 2017 was an ambitious mission of ”transforming the most important products in the world,” including football helmets. Studying Liquid Crystal Elastomers (LCEs), a soft, multifunctional elastic material, the Impressio team discovered their extraordinary ability to dissipate high levels of energy. Because of their ability to form a rubbery material, LCEs can absorb energy and dissipate it—a now-novel approach to reducing concussion risk in sports. By lining football helmets with the patented LCE, helmets are better equipped to dissipate the force absorbed during a big hit or collision.

“Concussions, and personal protection more broadly, are a hot topic right now in football as well as many other areas including personal mobility, construction, and defense,” Yakacki said. “People are looking for solutions, and new technology can provide answers. By improving the materials and the way they are designed in helmets, they can absorb and guide energy better, therefore reducing concussion risk and improving comfort for all helmet wearers.”

The NFL Helmet Challenge’s goal is to stimulate the development by experts, innovators, and helmet manufacturers of a new helmet for NFL players that outperform, based on laboratory testing, all helmet models currently worn by NFL players. Coming to a close in October 2021, three teams – Impressio, Kollide, and Xenith – were awarded a total of $1.55 million in grant funding to “advance their designs and help the teams bring their technologies to players on the field as soon as possible.”
The material is unique in that it’s highly energy-absorbing, it’s highly rate-dependent, and it can mimic the natural tissues in your body, such as the cartilage or even muscle. Impressio’s approach to the NFL Helmet Challenge was to place their LCE material in tandem with a 3D-printed flexible lattice. The LCE material reacts to different impact conditions and absorbs energy, while the lattice provides optimal comfort and fits the head. When speaking of the difficulties of this challenge, Yakacki said, “None of the materials that we put on the inside are used in a commercially-available helmet right now. These are brand-new materials that have never been used before.”
To help overcome these challenges, Impressio has relied on the talented CU Denver student body. The majority of Impressio’s team are CU Denver alum. “We’ve been able to provide a wide range of sponsored research, internship, and employment opportunities to CU Denver students and graduates,” says Yakacki. Lyssa Bell (MSME 2021) was a graduate student intern at Impressio and then was hired full-time. “I feel very fortunate to have gotten my foot into the door of a project like this right out of grad school. It was a unique and rewarding learning experience and an important challenge to have been involved in, and I’m excited to see where it goes” says Bell.

The teams in the NFL Challenge were selected by a panel of judges that included two NFL Legends and a number of experts in engineering, neurology, sports business, and biomechanics. Impressio was awarded $454,000. A video of the awardees can be viewed here. Impressio plans to use the award to manufacture their material at scale and ready production for commercialization.