Faculty

Burleson earns 2025 Exceptional Graduate Faculty Mentor Award

Alexander James Servantez — Tue, 13 May 2025 20:53:08 +0000

Burleson earns 2025 Exceptional Graduate Faculty Mentor Award Alexander Jame… Tue, 05/13/2025 - 14:53

Assistant Professor Grace Burleson has earned the Graduate School's 2025 Exceptional Graduate Faculty Mentor Award for her outstanding contributions to mentoring individual graduate students and improving the overall climate of graduate education.

Off

Traditional

White

New discovery shows how molecules can mute heat like music

Alexander James Servantez — Wed, 07 May 2025 03:00:00 +0000

New discovery shows how molecules can mute heat like music Alexander Jame… Tue, 05/06/2025 - 21:00

Alexander Servantez

Imagine you are playing the guitar—each pluck of a string creates a sound wave that vibrates and interacts with other waves.

Now shrink that idea down to a small single molecule, and instead of sound waves, picture vibrations that carry heat.

Ultra-high vacuum scanning probe setup modified by the Cui Research Group to conduct thermal microscopy experiments.

A team of engineers and materials scientists in the Paul M. Rady Department of Mechanical Engineering at CU Boulder has recently discovered that these tiny thermal vibrations, otherwise known as phonons, can interfere with each other just like musical notes—either amplifying or canceling each other, depending on how a molecule is "strung" together.

Phonon interference is something that’s never been measured or observed at room temperature on a molecular scale. But this group has developed a new technique that has the power to display these tiny, vibrational secrets.

The breakthrough study was led by Assistant Professor Longji Cui and his team in the Cui Research Group. Their work, funded by the National Science Foundation in collaboration with researchers from Spain (Instituto de Ciencia de Materiales de Madrid, Universidad Autónoma de Madrid), Italy (Istituto di Chimica dei Composti Organometallici) and the CU Boulder Department of Chemistry, was recently published in the journal Nature Materials.

The group says their findings will help researchers around the world gain a better understanding of the physical behaviors of phonons, the dominant energy carriers in all insulating materials. They believe one day, this discovery can revolutionize how heat dissipation is managed in future electronics and materials.

“Interference is a fundamental phenomenon,” said Cui, who is also affiliated with the Materials Science and Engineering Program and the Center for Experiments on Quantum Materials. “If you have the capability to understand interference of heat flow at the smallest level, you can create devices that have never been possible before.”

The world’s strongest set of ears

Cui says molecular phononics, or the study of phonons in a molecule, has been around for quite some time as a primarily theoretical discussion. But you need some pretty strong ears to “listen” to these molecular melodies and vibrations first-hand, and that technology just simply hasn’t existed.

A sneak peek into the ultra-high vacuum scanning probe microscopy setup used to conduct molecular measurements.

That is, until Cui and his team stepped in.

The group designed a thermal sensor smaller than a grain of sand or even a sawdust particle. This little probe is special: it features a record-breaking resolution that allows them to grab a molecule and measure phonon vibration at the smallest level possible.

Using these specially designed miniature thermal sensors, the team studied heat flow through single molecular junctions and found that certain molecular pathways can cause destructive interference—the clashing of phonon vibrations to reduce heat flow.

Sai Yelishala, a PhD student in Cui’s lab and lead author of the study, said this research using their novel scanning thermal probe represents the first observation of destructive phonon interference at room temperature.

In other words, the team has unlocked the ability to manage heat flow at the scale where all materials are born: a molecule.

“Let’s say you have two waves of water in the ocean that are moving towards each other. The waves will eventually crash into each other and create a disturbance in between,” Yelishala said. “That is called destructive interference and that is what we observed in this experiment. Understanding this phenomenon can help us suppress the transport of heat and enhance the performance of materials on an extremely small and unprecedented scale.”

Tiny molecules, vast potential

Developing the world’s strongest set of ears to measure and document never-before-seen phonon behavior is one thing. But just what exactly are these tiny vibrations capable of?

PhD student and lead author of the study Sai Yelishala (right), along with Postdoctoral Associate and second author Yunxuan Zhu (left). Both are members of the Cui Research Group led by Assistant Professor Longji Cui.

“This is only the beginning for molecular phononics,” said Yelishala. “New-age materials and electronics have a long list of concerns when it comes to heat dissipation. Our research will help us study the chemistry, physical behavior and heat management in molecules so that we can address these concerns.”

Take an organic material, like a polymer, as an example. Its low thermal conductivity and susceptibility to temperature changes often poses great risks, such as overheating and degradation.

Maybe one day, with the help of phonon interference research, scientists and engineers can develop a new molecular design. One that turns a polymer into a metal-like material that can harness constructive phonon vibrations to enhance thermal transport.

The technique can even play a large role in areas like thermoelectricity, otherwise known as the use of heat to generate electricity. Reducing heat flow and suppressing thermal transport in this discipline can enhance the efficiency of thermoelectric devices and pave the way for clean energy usage.

The group says this study is just the tip of the iceberg for them, too. Their next projects and collaborations with CU Boulder chemists will expand on this phenomenon and use this novel technique to explore other phononic characteristics on a molecular scale.

“Phonons travel virtually in all materials,” Yelishala said. “Therefore we can guide advancements in any natural and artificially made materials at the smallest possible level using our ultra-sensitive probes.”

Assistant Professor Longji Cui and his team in the Cui Research Group have developed a new technique that allows them to measure phonon interference inside of a tiny molecule. They believe one day, this discovery can revolutionize how heat dissipation is managed in future electronics and materials.

Off

Traditional

White

An artistic rendering showing thermal phonon interference in a molecule, otherwise known as "a molecular song."

Jayaram nabs prestigious grants to design insect-inspired, shapeshifting robots

Alexander James Servantez — Tue, 29 Apr 2025 16:57:24 +0000

Jayaram nabs prestigious grants to design insect-inspired, shapeshifting robots Alexander Jame… Tue, 04/29/2025 - 10:57

Assistant Professor Kaushik Jayaram is the recipient of a $650,000 CAREER award from the U.S. National Science Foundation. The funding will help Jayaram make advancements in robots by drawing from what might seem to be an unlikely source: insects and other small creatures.

Off

Traditional

White

Boulder’s Mana Battery is in race to perfect sodium-ion battery technology

Alexander James Servantez — Mon, 07 Apr 2025 18:12:41 +0000

Boulder’s Mana Battery is in race to perfect sodium-ion battery technology Alexander Jame… Mon, 04/07/2025 - 12:12

Associate Professor Chunmei Ban is a co-founder of CU Boulder spinout Mana Battery. The company is at the forefront of a race to provide low-cost batteries with longer lifespans than the market offers today.

Off

Traditional

White

Borden, Rentschler inducted into the AIMBE College of Fellows

Alexander James Servantez — Mon, 31 Mar 2025 19:24:59 +0000

Borden, Rentschler inducted into the AIMBE College of Fellows Alexander Jame… Mon, 03/31/2025 - 13:24

Professors Mark Borden and Mark Rentschler have been inducted into the American Institute for Medical and Biological Engineering (AIMBE) College of Fellows. The program is among the highest professional distinctions given to medical and biological engineers, representing the top 2% of these engineers around the world.

Off

Traditional

White

From research to impact: Massimo Ruzzene

Alexander James Servantez — Mon, 31 Mar 2025 15:52:12 +0000

From research to impact: Massimo Ruzzene Alexander Jame… Mon, 03/31/2025 - 09:52

Professor Massimo Ruzzene is the senior vice chancellor for research and innovation. His goal is to foster a campus environment that turns research into real-world impact in areas such as quantum, space, climate and health.

Off

Traditional

White

Sustainable Spinouts: Innovation in Action

Alexander James Servantez — Fri, 21 Mar 2025 17:22:08 +0000

Sustainable Spinouts: Innovation in Action Alexander Jame… Fri, 03/21/2025 - 11:22

CU Boulder is a hub for sustainable entrepreneurship. Spinouts such as Associate Professor Greg Rieker's LongPath Technologies, Professor Se-Hee Lee's Solid Power and Associate Professor Chunmei Ban's Mana Battery are just some of the university's latest successful ventures motivated by protecting the environment.

Off

Traditional

White

CU Boulder startup Mesa Quantum earns two major grants to improve navigation infrastructure

Alexander James Servantez — Fri, 21 Mar 2025 16:45:19 +0000

CU Boulder startup Mesa Quantum earns two major grants to improve navigation infrastructure Alexander Jame… Fri, 03/21/2025 - 10:45

For over 20 years, Associate Research Professor Svenja Knappe has focused on developing miniaturized quantum sensors and systems. Now the technology is helping CU Boulder spinout Mesa Quantum commercialize chip-scale quantum solutions that can transform our navigation infrastructure.

Off

Traditional

White

People of color breathe Denver’s smelliest air

Alexander James Servantez — Mon, 17 Mar 2025 21:17:27 +0000

People of color breathe Denver’s smelliest air Alexander Jame… Mon, 03/17/2025 - 15:17

A new CU Boulder-led study, headlined by Professor Shelly Miller, shows that Denver residents in marginalized areas of the city are more likely to be exposed to odor emitting facilities. However, these communities are also the least likely to report these odors to the city, a statistic that Miller and her colleagues would like to see change.

Off

Traditional

White

Mukherjee, Vance named 2025 RIO Faculty Fellows

Alexander James Servantez — Thu, 13 Mar 2025 15:53:41 +0000

Mukherjee, Vance named 2025 RIO Faculty Fellows Alexander Jame… Thu, 03/13/2025 - 09:53

Assistant Professor Debanjan Mukherjee and Associate Professor Marina Vance have both been selected as 2025 RIO Faculty Fellows. The program supports faculty in achieving their research and innovation goals and promotes collaboration through tailored training, experiential learning and leadership development opportunities.

Off

Traditional

White