Mechanical Engineering Associate Professors Corinne Henak and Melih Eritan developed a portable device patented by WARF that tests the failure threshold of soft materials, helps design medical devices, and diagnoses tissue damage.
Sound moves through the air as undulating waves of pressure, which sensory receptors on the tiny stereocilia hairs in our ear convert into mechanical vibrations that the brain interprets as sound. In mechanical engineering, a similar process is used to detect structural and mechanical failures: vibratory sensors detect frequency shifts in sound waves traveling through hard materials like ceramics or concrete, revealing unseen cracks or structural integrity variations.
Acoustic emissions technology is typically designed for understanding stresses and strains in hard materials, like bone implants, dental crowns, and prostheses. However, a new technology recently developed by UW-Madison Mechanical Engineering Associate Professors Melih Eriten and Corinne Henak extends this acoustic method to soft materials.
Their invention, a non-contact, portable vibrometer, was nominated as a finalist for the 2022 Wisconsin Alumni Research Foundation (WARF) Innovation Award because of the device’s potential for “long-term impact with broad benefits for humankind.” The vibrometer will help biomechanical engineers predict the likelihood of ruptures and tears in soft materials based on increasingly accurate measurements of surface shear waves, stiffness, and toughness.
For Henak, the invention and patent are a culmination of her research in biomechanics. “Biomechanics has been my interest area since I started doing research as a first-year undergraduate,” Henak says. “[The field] has a personal resonance based on family members’ experiences with injury, and a captivating potential to help people.”
“Because of the complexity of biological tissues, it’s easy to get hooked on digging into the questions of how they function.”
Corinne Henak
Henak’s long standing collaboration with Eriten was key to creating the device, which built off Eriten’s expertise in acoustic emissions (AE), laser vibrometry, and their shared research in cartilage fracture and cartilage-inspired dampers.
Potential applications of the acoustic emissions detector include designing new medical devices that incorporate foam and soft polymers, precisely controlling how soft foods are processed and cut, and diagnosing tissue damage with a minimally invasive procedure. A variation of the invention includes an optical fiber and probe that could be incorporated into a scalpel for surgical procedures.
“I am excited about the many potential application areas. Moving forward, we have a planned path, but still have the possibility to look in other directions,” Henak adds.
Hennak leads amongst women inventors. According to the National Science Board, in 2022 the share of women inventors on patents registered in the United States was lowest in the field of mechanical engineering at roughly 6%.
“I found the process to be very collaborative between inventors and WARF. Their proactive efforts in talking to faculty about the Innovation Disclosure Report (IDR) process has been very helpful for empowering disclosure,” Henak says.
Disclosure is the process of describing an invention, discovery, or idea to a technology transfer office to protect future intellectual property before commercialization. WARF has identified disclosure as a key window to address this gender disparity through straightforward approaches that include devotion to clarity and accessibility in online disclosure forms.
According to Henak, “This was not the first IDR that I had submitted, and prior ones had clarified two things: that early disclosure is always better and that it’s low risk to submit an IDR.”
Henak’s invention represents an optimal outcome for disclosure empowerment and a new technology for soft tissue characterization in industries facing design challenges in durability and biocompatibility.