Research Briefs 2024
Shape-shifting display adds touch to digital world
In a new study, a team of mechanical engineering and materials science researchers have created a one-of-a-kind shape-shifting display that fits on a card table. The device is made from a grid of soft robotic “muscles” that can sense outside pressure and pop up to create patterns.
It’s precise enough to generate scrolling text and fast enough to shake a chemistry beaker filled with fluid. It may also deliver something even rarer: the sense of touch in a digital age.
“As technology has progressed, we started with sending text over long distances, then audio and now video,” said Brian Johnson (PhDMechEngr’22), one of two lead authors of the new study. “But we’re still missing touch.”
The group’s innovation builds off a class of soft robots pioneered by a team led by former CU Boulder faculty member Christoph Keplinger. They’re called Hydraulically Amplified Self-Healing ELectrostatic (HASEL) actuators.
The prototype display isn’t ready for the market yet. But the researchers envision that, one day, similar technologies could lead to sensory gloves for virtual gaming or a smart conveyor belt that can undulate to sort apples from bananas.
Revolutionizing how heat is handled in computers
Sanghamitra Neogi of the Ann and H.J. Smead Department of Aerospace Engineering Sciences is leading a multi-university research team to revolutionize how manufacturers model and deal with heat in computers.
It is well documented that microchips and transistors fail due to heating challenges. Mitigation to this point has primarily been through bigger fans and cooling channels, but as chips have gotten smaller to pack in more processing power, heat has become a larger issue.
“With microelectronics, we are moving away from planar chips to 3D stacked chips because it makes memory and processing quicker, but you can’t cool the inner channels using regular methods because you don’t have the real estate. The current ideas don’t work very well,” Neogi said.
Neogi and her team will start by creating a computational thermal model of individual transistors at the deeply scaled nanometer level and then expand the model to a millimeter-scale circuit element with 300,000 transistors.
Neogi is excited about the project’s alignment with the federal CHIPS Act of 2022, which seeks to dramatically expand semiconductor research and development in the United States.
Does better air mean fewer sick days for kids?
Engineers at CU Boulder – led by Mark Hernandez of civil, environmental and architectural engineering – kicked off a new project in September to investigate whether improving classroom air quality with air purifiers can help students miss fewer school days.
The study comes at a time when millions of students across the country are chronically absent from school, a worsening trend that could have large impacts on students’ academic performance.
Hernandez and his team, including eight engineering students, helped install air quality monitors in 2,400 classrooms across Colorado’s K-12 schools. These monitors can provide teachers, school officials and researchers with real-time data on classroom temperature, humidity, CO2 and air pollutant levels.
Hernandez is co-leading the project with researchers at the CU Anschutz Medical Campus with a $2.2 million grant from the Centers for Disease Control and Prevention.
Hernandez started testing air purifiers in Denver Public Schools classrooms in 2020, in an effort to help reopen schools during the pandemic. The pilot trial’s data showed that the purifiers, when working properly, were effective in improving classroom ventilation and reducing air pollutants.
Working toward better avalanche, landslide prediction
Associate Professor Nathalie Vriend finds inspiration for her research in nature.
The mechanical engineer and physicist received a prestigious experiment physics award in 2023 from the Gordon and Betty Moore Foundation to further her research on granular flows in the natural environment. Ultimately, the work has the potential to advance the analysis, modeling and predicting of natural hazards like landslides, avalanches and ice formations.
In her laboratory experiments, Vriend uses a technique called photoelasticity that analyzes how patterns of light within particles change according to the magnitude and direction of forces exerted upon them. The changing patterns of light provide a picture of the stress distribution between particles in situations like rockslides or grains flowing out of a silo.
So far, Vriend has focused on dry granular flows, like sand and snow, but now she wants to introduce fluid between the particles. In addition to the solid contact forces already exerted onto the particles, this would add hydrodynamic stresses.
As an avid skier, Vriend for the news outlet The Conversation after the deadly Lake Tahoe avalanches early this year.
Colorado prisons at risk for natural disasters
Three-quarters of Colorado prisons are likely to experience a natural disaster in the coming years, but due to aging infrastructure and outdated policies, many are ill-equipped to keep residents safe, suggests new CU Boulder research.
The study, published in the journal Natural Hazards Review, came on the heels of one of the hottest summers on record and as U.S. lawmakers called for an investigation into a rash of what are believed to be heat-related deaths in the nation’s prisons.
In other research, including interviews and focus groups with 35 formerly incarcerated Coloradans, the researchers found that most had already suffered from climate-related hazards, experiencing everything from “brutally hot” or “ice cold” cells to respiratory problems related to wildfire smoke and lack of toilet facilities during floods.
“We showed that the incarceration infrastructure in Colorado is highly vulnerable to climate-related hazards and that incarcerated people who are Black and Hispanic are at even greater risk,” said Shideh Dashti, associate professor in the Department of Civil, Environmental and Architectural Engineering and co-author of both studies. “This is a serious racial justice and environmental justice issue that needs to be addressed.”
The research was supported by CU Engineering’s Resilient Infrastructure with Sustainability and Equity (RISE) interdisciplinary research theme.
Advancing engineered living materials research
Assistant Professor Kõnane Bay was drawn to CU Boulder by the growth of faculty expertise in soft materials in both the Material Science and Engineering Program and Department of Chemical and Biological Engineering.
Her soft-materials research portfolio explores a variety of applications and approaches, but generally centers on combining tiny microorganisms with fabricated materials to achieve new or unique properties. She said applications could include protective equipment like helmets that self-repair.
Bay added that while engineering fully synthetic materials with such capabilities remains a challenge, properties like regeneration are inherent to biofilm-forming bacteria, making them a likely path forward for the work. The challenge, she said, is in designing rules for these developing materials, such as how they bend or break.
“It’s all part of this growing research trend into engineered living materials that can be used in a variety of fields like construction, water treatment or medicine as well,” she said. “There is a lot of interest from federal funding agencies like the Department of Defense and Department of Energy as well as private companies.”