Category: Research Features

Paleomagnetism: Deciphering the Early History of the Earth

Rock samples in Smirnov’s lab are 2-3 billion years old.

Although it makes up about seven-eighths of the Earth’s history, the Precambrian time period is far from figured out. Key questions remain unanswered.

The Precambrian—the first four billion years of Earth history—was a time of many critical transitions in Earth systems, including oxygenation of the atmosphere and emergence of life. But many of these processes, and the links between them, are poorly understood.

Data can be obtained from fossil magnetism—some rocks record the Earth’s magnetic field that existed at the time of their formation. However, for very old rocks (billions of years old) the conventional methods of obtaining fossil magnetism do not work well.

Professor Aleksey Smirnov, Chair of the Department of Geological and Mining Engineering and Sciences

Michigan Tech Professor of Geophysics, Aleksey Smirnov, seeks to substantially increase the amount of reliable data on the Precambrian field. Smirnov investigates the fossil magnetism of well-dated igneous rocks from around the globe using new and experimental processes to help fill in the blanks. His work on the early magnetic field history is supported by several National Science Foundation grants including a National Science Foundation CAREER award.

“Deciphering the early history of our planet, the early history of its geomagnetic field, represents one of the great challenges in Earth science,” says Smirnov. “Available data are scarce, and key questions remain unanswered. For instance we still don’t know how and when the Earth’s geomagnetic field began.”

Smirnov and former student Danford Moore
drill rock samples in the Zebra Hill region, Pilbara Craton, Western Australia.

“How did the geomagnetic field evolve at early stages? How did it interact with the biosphere, and other Earth system components—these are all largely unanswered questions. There is also disagreement on the age of the solid inner core, ranging between 0.5 and 2.5 billion years,” note Smirnov.

Scientists largely believe the Earth’s intrinsic magnetic field is generated and maintained by convective flow in the Earth’s fluid outer core, called the geodynamo.

Smirnov’s research has broad implications for Earth science including a better understanding of the workings and age of the geodynamo.

Earth cutaway. Credit: Lawrence Livermore Lab

“Crystallization of the inner core may have resulted in a dramatic increase of the geomagnetic field strength preceded by a period of an unusually weak and unstable field,” he explains. “If we observe this behavior in the paleomagnetic record, we will have a much better estimate of the inner core age and hence a better constrained thermal history of our planet.”

Knowing the strength and stability of the early geomagnetic field is also crucial to understanding the causative links between the magnetic field and modulating the evolution of atmosphere and biosphere,” notes Smirnov.

An illustration of the Earth’s magnetic field. Credit NASA.

Today, the Earth’s magnetic field protects the atmosphere and life from solar and cosmic radiation. “Before the inner core formation, the geodynamo could have produced a much weaker and less stable magnetic field. An attendant weaker magnetic shielding would allow a much stronger effect of solar radiation on life evolution and atmospheric chemistry.”

Both graduate and undergraduate students work with Smirnov to conduct research, logging hours in his Earth and Environmental Magnetism Lab, traveling the world to collect specimens.

The Earth and Environmental Magnetism Lab at Michigan Tech: If you drop a metal object on the floor there, the shielding properties of the room can be lost.

“The primary (useful) magnetizations recorded by ancient rocks are usually very weak and are often superimposed by later (parasitic, secondary) magnetizations,” Smirnov explains. “In order to get to the primary magnetization, we have to remove the secondary magnetizations by incremental heatings of the samples in our specialized paleomagnetic furnaces. The heatings must be done in a zero magnetic field environment. This is one reason why we have the shielded room, which was specially built for our paleomagnetic lab. There are other shielded rooms around the country, but ours is the only one at Michigan Tech,” he notes.

“The second reason for having our instruments in the shielded room is that the magnetizations we measure are weak and our instruments are so sensitive that the Earth’s magnetic field can interfere with our measurements. In fact, in addition to the shielded room, each instrument inside has an additional magnetic shielding.”

Note that the shielded room was built before I came, by my predecessors Profs Jimmy Diehl and Sue Beske-Diehl.

Students in this photo (some now graduates) are performing liquid helium transfer into one of our cryogenic magnetometers. “We need to constantly keep the sensors at a very cold temperature (only a very few degrees above the absolute zero temperature) to provide their ultra-sensitivity,” says GMES professor and chair, Aleksey Smirnov. “It is based on the principle of superconductivity.”

On one month-long trip to the Pilbara Craton in northwest Western Australia, Smirnov and a student gathered 900 samples of well preserved, 2.7 to 3.5 billion year old Precambrian rocks. 

Smirnov stepped into the role of chair of the Department of Geological and Mining Engineering and Sciences last fall, but that won’t keep him too far from his research. “Any interested student should feel free to get in touch to learn more about research positions,” he says.

Investigations in Smirnov’s lab are not limited to the ancient field. Other interests include the application of magnetic methods for hydrocarbon exploration, magnetic mineralogy, magnetism of meteorites, biomagnetism, and plate tectonics.

Learn more

Aleksey Smirnov is the new Chair of Geological and Mining Engineering and Sciences

Clues To Earth’s Ancient Core

Sarah Sun: Nice shirt! Embroidered Electronics and Motion-Powered Devices

A prototype of a flexible electronic circuit. Stitch schematics such as this one can be used to create health-monitoring fabrics.

Sarah Sun shares her knowledge on Husky Bites, a free, interactive webinar this Monday, September 28 at 6 pm ET. Learn something new in just 20 minutes, with time after for Q&A! Get the full scoop and register at

What if your medical heart monitor was embroidered right on your shirt, in your favorite design? And what if it was powered by your own movements (no battery required)? And what if you could even design and order it yourself, right on the internet? Get ready to learn all about this, and more.

Join Dean Janet Callahan for supper along with Sarah Sun, an associate professor of mechanical engineering, and George Ochieze, a graduate student researcher in Dr. Sun’s Human-Centered Monitoring Lab at Michigan Tech.

Associate Professor Sarah Sun

Sun is the lead investigator of three National Science Foundation research grants totaling $1 million focused on wearable electronics. She is also the director of the Center for Cyber-Physical Systems within Michigan Tech’s Institute of Computing and Cybersytems ICC.

“I am passionate about using engineering solutions to solve health problems,” she says. “We’re trying to solve long-existing technical challenges to improve medical devices, and we’re developing new technologies, too, in order to enable more diagnosis solutions.”

One of Sun’s large research projects involves developing new human interfaces for monitoring medical vital signs.

Their goal: to provide a reliable, personalized monitoring system that won’t disturb a patient’s life, whether at home, while driving, or at work. “Right now for patients there’s a real trade-off between comfort and signal accuracy. This tradeoff can interfere with patient care and outcomes, too,” she explains.

Sun hopes to use electrophysiological sensing and motion sensing to help prevent automobile crashes, especially those that occur when drivers accidentally fall asleep at the wheel. According to the National Highway Traffic Safety Administration, while the precise number can be hard to nail down, drowsy driving is a factor in more than 100,000 crashes in the U.S each year, resulting in nearly 1,000 deaths and 50,000 injuries.

First, though, Sun and her team needed to figure out how to overcome a major challenge in monitoring vital signs: motion artifacts, or glitches caused by the slightest patient movement, even shivering, or tremors.

Motion artifacts appear in an ECG when the patient moves.

“ECG, a physiological signal, is the gold standard for diagnosis and treatment of heart disease, but it is a weak signal,” Sun explains. “Especially when monitoring a weak signal, motion artifacts arise.”

Sun and her team first set out to discover the mechanism underlying the phenomenon of motion artifacts. Then, they realized they were able to tap into it. 

“We not only reduce the influence of motion artifacts but also use it as a power resource,” she says. The result: a sensing device that harvests energy from patient movements.

Sun cites recent progress in the development and manufacturing of smart fabrics, textiles, and garments. “This has opened the door for next-generation wearable electronics—fully flexible systems that can be embroidered directly onto cloth,” she says.

“Feel free to download our .exp files for your own wearable system on cloth manufacturing. The code can be processed by regular sewing machines. Just go online to WEF, our new Wearable Electronics Factory.

Sarah Sun, Mechanical Engineering Assoc. Professor at Michigan Tech

By using conductive thread and passive electronics—tiny semiconductors, resistors and capacitors—Sun is able to turn logos into wearable electronics. The stitches themselves become the electronic circuit. Sun and her team can embroider on just about anything flexible, including cloth, foam, and other materials. 

Sun is also building a manufacturing network and cloud-based website where stitch generation orders can be made. “In the future, a person can upload their embroidery design to generate stitches, or download certain stitches as needed,” she says. The lab provides coding for the electronics and stitch generation to embroiderers. “Soon any embroidery company will have the potential to manufacture embroidered health monitors,” she says.

These wearable, embroidered ”E-logos” can monitor multiple vital signals. They’re customizable, too. 

Sun hopes flexible, wearable electronics will interest a new generation of engineers by appealing to their artistic sides. “This type of embroidery circuit really brings together together craft and functional design.” 

Mechanical Engineering PhD student George Ochieze arrived on campus at Michigan Tech in 2019. He grew up in Abia, Nigeria and earned his bachelor of engineering at Federal University of Technology Owerri in 2017.

George Ochieze is pursuing a master’s degree in Mechatronics and a PhD in Mechanical Engineering. He took Sun’s Introduction to Mechatronics and Robotics course at Michigan Tech last spring. That’s when he discovered his own passion: working with machines and control devices. He joined her research group last summer.

Mechatronics uses electromechanical systems automated for the design of products and processes,” Ochieze explains. “I picked up my research interest after modeling an RRR manipulator using CAD software. That’s a robot manipulator set up with 3 revolute joints. I had some challenges in controlling the joints, and Dr. Sun gave me some tips. She was very helpful in guiding me through the process, and our mentor/mentee relationship in soft robotics was formed,” says Ochieze.

Soft Robotics involves the design and construction of robots from flexible, compliant materials, drawing from the movements and adaptations of living organisms. Soft robots offer new capabilities, as well as improved safety when working around humans, with potential use in medicine and manufacturing.

Ochieze plans to share a demo on soft robotics during Husky Bites.

“Throughout my growth in the engineering field, I have been surrounded by people who are generous enough to share their knowledge. I look forward to mentoring others like me within this field.”

Professor Sun, when did you first get into engineering? What sparked your interest?

My dad liked to play with old electronics when I was young. I built my first radio receiver in middle school with him although I did not know how those electronics work at that time. This experience really inspired my interest in pursuing an engineering degree. I earned my bachelor’s degree at Tianjin University. It’s located near Beijing, in Tianjin, China, on the Bohai Sea. About six year ago, I earned my PhD in electrical engineering at Case Western Reserve University in Cleveland, Ohio. My doctoral research was on wearable electronics.

Sarah Sun's hands hold electronic embroidery showing the stitches that function as circuits

Family and Hobbies?

I grew up in Northern China, in a town with a very cold winter climate, but dry. My husband came to Michigan Tech first. He liked the U.P. a lot and told me lots of great things about Tech.  It was challenging for me to balance work and life at first, especially with two little kids. My son, Brent, is almost 8 now, and my daughter, Leah, is two. My husband and I both like to design and build stuff, so we enjoy it with our kids, too. 

George, how did you first get into engineering? What sparked your interest?

I grew up in Aba, in Abia, Nigeria. Working in my Dad’s fabrication company fostered my interest in the engineering field. At a young age I became familiar with machine operations. I was fascinated with the sequence operation of machines to achieve a desired goal. I started developing cars and movable structures with available materials, leading my fellow students in the design of mechanical components.

Graduate student George Ochieze in the Human-Centered Monitoring Lab at Michigan Tech. His passion and research focus: soft robotics.

Do you do any mentoring or teaching on campus?

I am one of two instructors in Michigan Tech’s Career and Technical Education (CTE) Mechatronics program for local high school juniors and seniors. Even in difficult times during the pandemic, these young scholars show overwhelming potential to conquer the mechatronics field—a glimpse into a welcoming future in engineering. They will go on to find degree pathways at Michigan Tech, and excellent careers in smart manufacturing.

Read and View More

Vital signs—Powering Heart Monitors with Motion Artifacts

Ye Sun Wins CAREER Award

Human Centered Monitoring Laboratory (HCML)

Stitches into Circuits (check out the video, below)

Stitch Generation

Chad Deering: Predicting Volcanic Unrest Via Plant Life Stress

Vegetative stress at the foot of the Kīlauea Volcano in Hawaii

After a volcanic eruption, it can take years for vegetation to recover, and landscapes are often forever changed. But well before any eruption takes place, the assemblage of plant species on and around the volcano show signs of stress, or even die off. 

Chad Deering

Chad Deering, a volcanologist in the Department of Geological and Mining Engineering and Sciences at Michigan Technological University uses hyperspectral remote sensing data, acquired during an airborne campaign over Hawaii, to predict future volcanic eruptions on the Big Island. Deering and his team of graduate students from Michigan Tech are collaborating with scientists from the NASA Jet Propulsion Laboratory (JPL), and the University of New Mexico. 

“The replenishment of a shallow magma reservoir can signal the onset of an eruption at a dormant volcanic system, such as at Mauna Loa. It can also indicate significant changes in eruptive behavior at an already active volcano, as in what occurred at Kīlauea,” Deering says. 

“Rising magma ultimately results in a flux of volatiles through the ground, including carbon dioxide and sulfur dioxide. Active vent plumes of those same gases include particulate matter, even thermal energy, and those often enter the atmosphere, as well. “

By detecting and characterizing those fluxes and their effects on the health and extent of local vegetation, Deering is able to recognize significant changes in a volcano’s behavior. The result: a new, cost-effective way to forecast volcanic hazards and events.

“Monitoring vegetative stress on a volcano can potentially provide a much-needed early warning system for those living near and around volcanoes,” adds Deering. An estimated 500 million people are living in danger zones around the world.

“Our preliminary results indicate a strong correlation between emissions of carbon dioxide and hydrogen sulfide gas from soil—as well as the thermal anomalies—and different aspects of vegetative stress.” 

Deering’s team uses highly sensitive hyperspectral analysis to distinguish between effects of different gas species and thermal anomalies on variations in vegetative stress. “This is important as CO2 and H2S have different solubilities in magma. That allows us a semi-quantitative measure of the depth of magma as it rises.

With the results of their study, the team developed a remote-sensing automated detection algorithm that can be used in satellite-based platforms to detect volcanic unrest at volcanoes worldwide. 

“In particular, this tool will allow the scientific community to monitor volcanoes that are otherwise inaccessible due to heavy vegetation and/or their remote locations,” adds Deering. “It will also remove technical barriers such as establishing extensive and expensive seismic arrays that are difficult to maintain.”

NASA gathered the hyperspectral data over the course of a year, starting in 2017. Deering and his team are now analyzing more recent data, collected last year. “We want to determine whether we could have predicted the recent volcanic fissure emergence and activity taking place in Hawaii.”

Biofuels and Dry Spells: Switchgrass Changes During a Drought

High yields. A deep root system that prevents soil erosion and allows for minimal irrigation. The ability to pull large amounts of carbon out of the air and sequester it in the soil. Beneficial effects on wildlife, pollination, and water quality. Perennial grasses, such as switchgrass and elephant grass, are wonderful in many ways and especially promising biofuel feedstocks. But that promise, a team of researchers discovered, may evaporate during a drought.

“The characteristics of any living organism are linked to their genetics and the environment they experience during growth,” says Rebecca Ong, an assistant professor of chemical engineering at Michigan Technological University. “Bioenergy production is no different. It’s a chain where every link, including the feedstock characteristics, influences the final product—the fuel.”

Ong is both a chemical engineer and a biologist. She holds a unique perspective on how the bioenergy system fits together, which comes in handy, especially now, in light of a recent puzzling discovery.

“Plants have lower biomass yields during a drought. You understand this when you don’t need to mow your lawn after a dry spell,” she explains. “The same is true with switchgrass. Besides the expected effect on crop yields, we were completely unable to produce fuel from switchgrass—using one of our standard biofuel microbes—grown during a major drought year.”

“At the lab scale this is an interesting result. But at the industrial scale, this could potentially be devastating to a biorefinery,” she says.

Ong, her research team, and colleagues within the Great Lakes Bioenergy Research Center (GLBRC), a cross-disciplinary research center led by the University of Wisconsin–Madison, are making efforts to understand, pulling in researchers from across the production chain to study the problem. 

Ong is the only Michigan Tech faculty member in the GLBRC. “Our team was able to identify some of the compounds formed in the plant in response to drought stress, contributing to the inhibition. But plant materials are very complex. We’ve only scratched the surface of what is in there. We have much more to learn.”

The first step, she says, is to understand what inhibits fuel production. “Once we know that, we can engineer solutions: new, tailor-made plants with improved characteristics, as well as modifications to processing, such as the use of different microbes, to overcome these issues.”

Ong points out that in the U.S., gasoline is largely supplemented with E10 ethanol, derived from sugars in corn grain. However renewable fuels can be produced from any source of sugars—including perennial grasses, which if planted on less productive land do not conflict with food production.

“Ultimately, if we are to replace fossil energy in the long term, we need a broad alternative energy portfolio,” says Ong. “We need industry to succeed. We are engaging in highly collaborative research to ensure that happens.”

Seismic Reflections: Siting the Gordie Howe Bridge

The Gordie Howe International Bridge connecting Windsor, Ontario, and Detroit, Michigan is currently under construction and expected to be complete in 2024 at a cost of $5.7 billion.  The bridge is named in recognition of the legendary hockey player, a Canadian who led the Detroit Red Wings to four Stanley Cup victories.

The construction of any large infrastructure project requires a strong foundation, especially one with the longest main span of any cable-stayed bridge in North America—namely, the Gordie Howe International Bridge over the Detroit River. More than a decade before ground was broken, careful siting of the bridge began to take place. By 2006 the list of possible crossings had been narrowed down to just two options.

Historical records from the early 1900s indicated that solution mining for salt had taken place on both sides of the river close to where the bridge was to be built. On the Michigan side, collapsed salt cavities caused sink holes located on nearby Grosse Isle. It was imperative that any salt cavities in the bridge construction area be found and avoided.

Seismologists Roger Turpening and Carol Asiala at Michigan Technological University

Seismologists Roger Turpening and Carol Asiala at Michigan Technological University were tasked by American and Canadian bridge contractors to select the best seismic method for searching for any cavities in the two proposed crossings—referred to at the time as “Crossing B” and “Crossing C”—and to interpret all resulting seismic images.

“Given the task to image a small target deep in the Earth, a seismologist will quickly ask two important questions: How small is ‘small?’ and How deep is ‘deep’? That’s because these two parameters conflict in seismic imaging,“ Turpening says.

“Seismic waves—vibrations of the Earth—are attenuated severely as they propagate through the Earth,” he explains. “Imaging small targets requires the use of high-frequency, seismic energy. When seismic sources and receivers are confined to the Earth’s surface, which is the usual case, waves must propagate downward through the Earth, reflect off of the target, and return to the surface. Soil, sand, and gravel in the surface layer overwhelmingly cause the greatest harm to image resolution, and the ray paths must pass through this zone twice.”

Turpening was one of the early developers of a technique called vertical seismic profiling, or VSP. “Seismic receivers are placed inside a vertical hole near the target. With the seismic source placed on the surface some distance from the hole, it’s possible to explore a region around the hole with ray paths that need to pass through the surface layer only once,” he says. “If the target is very important, we can drill a second hole and place the seismic source in it. Now we have even higher resolution because all of the ray paths are in the rock formations with low attenuation.”

The downside? “We can only make images of the region between the two holes. But if the target is extremely important in a limited area, we can use many boreholes and many images in the search. Given enough boreholes, a block of earth can be imaged with cross-well seismic reflection techniques.

A cross-well, seismic reflection image between test boreholes. The cavity is sharply seen because the shale stringers in the B-Salt (at the bottom of the image) are abruptly terminated. The cavity is approximately 375 ft. wide.

To site the Gordon Howie bridge, Turpening and Asiala chose a frequency band of 100Hz to 2 KHz—much higher than could be used with surface sources and surface receivers—for surveys on both sides of the river. This yielded high resolution seismic images, crucial for detecting cavities—and indeed they found one—on the Canadian side.

“The high-resolution imaging made it easy for us to spot missing shale stringers in the B-Salt layer in that image,” says Turpening. “This made the final selection of the bridge location simple. We found the cavity between boreholes X11-3 and X11-4, thus forcing the Canadians to chose Crossing B.  Obviously, the Michigan group had to, also, choose Crossing B.”

On the US side of the river geologist Jimmie Diehl, Michigan Tech professor emeritus, provided corroborating borehole gravity data.

Inspired by nature—Getting underwater robots to work together, continuously

Nina Mahmoudian, Mechanical Engineering-Engineering Mechanics
Nina Mahmoudian, Mechanical Engineering-Engineering Mechanics

Imagine deploying multiple undersea robots, all in touch and working together for months, even years, no matter how rigorous the mission, brutal the environment, or extreme the conditions.

It is possible, though not quite yet. “Limited energy resources and underwater communication are the biggest issues,” says Michigan Tech Researcher Nina Mahmoudian. Grants from a National Science Foundation CAREER Award and the Young Investigator Program from the Office of Naval Research are helping Mahmoudian solve those issues and pursue her ultimate goal: the persistent operation of undersea robots.

“Autonomous underwater vehicles (AUVs) are becoming more affordable and accessible to the research community,” she says. “But we still need multipurpose long-lasting AUVs that can adapt to new missions quickly and easily.”

Mahmoudian has already developed a fleet of low-cost, underwater gliders, ROUGHIEs, to do just that. Powered by batteries, they move together through the water simply by adjusting their buoyancy and weight. Each one weighs about 25 pounds. “ROUGHIE, by the way, stands for Research-Oriented Underwater Glider for Hands-on Investigative Engineering,” adds Mahmoudian.

“My most exciting observation was a Beluga mother and calf swimming together. It’s very similar to our recharge on-the-fly concept.”

Nina Mahmoudian

“The ROUGHIE’s open control architecture can be rapidly modified to incorporate new control algorithms and integrate novel sensors,” she explains. “Components can be serviced, replaced, or rearranged in the field, so scientists can validate their research in situ.” Research in underwater control systems, communication and networking, and cooperative planning and navigation all stand to gain.

Mahmoudian observes Mother Nature to design robotic systems. “There is so much to learn,” she says. “My most exciting observation was a Beluga mother and calf swimming together. It’s very similar to our recharge on-the-fly concept. The technology is an early stage of development.”

Mahmoudian’s students apply and implement their algorithms on real robots and test them in real environments. They also give back to the community, by teaching middle school students how to design, build, and program their own low-cost underwater robots using a simple water bottle, called a GUPPIE.

“As a girl growing up, I first thought of becoming an architect,” says Mahmoudian. “Then, one day I visited an exhibition celebrating the 30th anniversary of space flight. That’s when I found my passion.” Mahmoudian went on to pursue aerospace engineering in Iran, and then graduate studies at Virginia Tech in the Department of Aerospace and Ocean Engineering. “Underwater gliders share the same physical concepts as airplanes and gliders, but deal with different fluid density and interactions,” she says.

Now at Michigan Tech, Mahmoudian’s work advances the abilities of unmanned robotic systems in the air, on land, and under sea. “Michigan Tech has easy access to the North Woods and Lake Superior—an ideal surrogate environment for testing the kind of autonomous systems needed for long term, challenging expeditions, like Arctic system exploration, or searching for signs of life on Europa, Jupiter’s moon.” She developed the Nonlinear and Autonomous Systems Laboratory (NAS Lab) in 2011 to address challenges that currently limit the use of autonomous vehicles in unknown, complex situations.

More than scientists and engineers, Mahmoudian wants simple, low-cost AUV’s to be available to anyone who may need one. “I envision communities in the Third World deploying low-cost AUVs to test and monitor the safety and quality of the water they use.”

Demand dispatch—Balancing power in the grid in a nontraditional way

According to the National Renewable Energy Lab (NREL), distributed energy resources like these photovoltaic (PV) systems in a Boulder neighborhood—especially when they are paired with on-site storage—may eventually make large centralized power plants obsolete. Photo Credit: Topher Donahue
According to the National Renewable Energy Lab (NREL), distributed energy resources like these photovoltaic (PV) systems in a Boulder neighborhood—especially when they are paired with on-site storage—may eventually make large centralized power plants obsolete. Photo Credit: Topher Donahue

Traditionally, in the electric power grid, generation follows electric power consumption, or demand. Instantaneous fluctuation in demand is primarily matched by controlling the power output of large generators.

Sumit Paudyal, Electrical & Computer Engineering
Sumit Paudyal, Electrical & Computer Engineering

As renewable energy sources including solar and wind power become more predominant, generation patterns have become more random. Finding the instantaneous power balance in the grid is imperative. Demand dispatch—the precise, direct control of customer loads—makes it possible.

Michigan Tech researcher Sumit Paudyal and his team are developing efficient real-time control algorithms to aggregate distributed energy resources, and coordinate them with the control of the underlying power grid infrastructure.

“Sensors, smart meters, smart appliances, home energy management systems, and other smart grid technologies facilitate the realization of the demand dispatch concept,” Paudyal explains.

“The use of demand dispatch has promising potential in the US, where it is estimated that one-fourth of the total demand for electricity could be dispatchable using smart grid technologies.”

Sumit Paudyal

Coordination and control in real time is crucial for the successful implementation of demand dispatch on a large scale. “Our goal is to enable control dispatch distributed resources for the very same grid-level applications—frequency control, regulation, and load following—traditionally provided by expensive generators,” adds Paudyal.
“We have solved the demand dispatch problem of thermostatically-controlled loads in buildings and electric vehicle loads connected to moderate-size power distribution grids. The inherent challenge of the demand dispatch process is the computational complexity arising from the real-time control and coordination of hundreds to millions of customer loads in the system,” he adds. “We are now taking a distributed control approach to achieve computational efficiency in practical-sized, large-scale power grids.”

Vital signs—Powering heart monitors with motion artifacts

Electrocardiogram research Ye Sarah Sun

More than 90 percent of US medical expenditures are spent on caring for patients who cope with chronic diseases. Some patients with congestive heart failure, for example, wear heart monitors 24/7 amid their daily activities.

Ye Sarah Sun
Ye Sarah Sun, Mechanical Engineering-Engineering Mechanics

Michigan Tech researcher Ye Sarah Sun develops new human interfaces for heart monitoring. “There’s been a real trade-off between comfort and signal accuracy, which can interfere with patient care and outcomes,” she says. Sun’s goal is to provide a reliable, personalized heart monitoring system that won’t disturb a patient’s life. “Patients need seamless monitoring while at home, and also while driving or at work,” she says.

Sun has designed a wearable, self-powered electrocardiogram (ECG) heart monitor. “ECG, a physiological signal, is the gold standard for diagnosis and treatment of heart disease, but it is a weak signal,” Sun explains. “When monitoring a weak signal, motion artifacts arise. Mitigating those artifacts is the greatest challenge.”

Sun and her research team have discovered and tapped into the mechanism underlying the phenomenon of motion artifacts. “We not only reduce the in uence of motion artifacts but also use it as a power resource,” she says.

Their new energy harvesting mechanism provides relatively high power density compared with traditional thermal and piezoelectric mechanisms. Sun and her team have greatly reduced the size and weight of an ECG monitoring device compared to a traditional battery-based solution. “The entire system is very small,” she says, about the size of a pack of gum.

“We not only reduce the influence of motion artifacts but also use it as a power resource.”

Ye Sarah Sun

Unlike conventional clinical heart monitoring systems, Sun’s monitoring platform is able to acquire electrophysiological signals despite a gap of hair, cloth, or air between the skin and the electrodes. With no direct contact to the skin, users can avoid potential skin irritation and allergic contact dermatitis, too—something that could make long-term monitoring a lot more comfortable.

Ye Sarah Sun self-powered ECG heart monitor
Sun’s self-powered ECG heart monitor works despite a gap of hair, cloth or air between the user’s skin and the electrodes.

Where rubber becomes the road—Testing sustainable asphalt technologies

Zhanping You research team
A Michigan Tech research team led by Zhanping You tests a new, cooler way to make rubberized asphalt.

Over 94% of the roads in the United States are paved with asphalt mix. Each year, renovating old highways with new pavement consumes about 360 million tons of raw materials. It also generates about 60 million tons of old pavement waste and rubble.

Zhanping You, Civil & Environmental Engineering
Zhanping You, Civil & Environmental Engineering

Recycling these waste materials greatly reduces the consumption of neat, unmodified asphalt mix and lowers related environmental pollution. But blending recycled asphalt pavement (RAP) with fresh asphalt mix presents several challenges, potentially limiting its usefulness.

Not to Michigan Tech researcher Zhanping You. “One noticeable issue of using RAP in asphalt pavement is the relatively weaker bond between the RAP and neat asphalt, which may cause moisture susceptibility,” he explains. “Modifying the asphalt mix procedure and selecting the proper neat asphalt can effectively address this concern.”

You tests a variety of recycled materials to improve asphalt pavement performance. Crumb rubber, made from scrap tires, is one such material. “Crumb rubber used in asphalt reduces rutting and cracks, extends life, and lowers noise levels. Another plus—building one mile of road with crumb rubber uses up to 2,000 scrap tires. Hundreds of millions of waste tires are generated in the US every year,” he adds.

Adding crumb rubber to asphalt mix has its own share of problems. “When crumb rubber is blended into asphalt binder, the stiffness of the asphalt binder is increased. A higher mixing temperature is needed to preserve the flowability. Conventional hot-mix asphalt uses a lot of energy and releases a lot of fumes. We use a foaming process at lower temperatures that requires less energy and reduces greenhouse gas emissions.”

“Building one mile of road with crumb rubber uses up to 2,000 scrap tires. Hundreds of millions of waste tires are generated in the US every year.”

—Zhanping You

You and his team integrate state-of-the-art rheological and accelerated-aging tests, thermodynamics, poromechanics, chemical changes, and multiscale modeling to identify the physical and mechanical properties of foamed asphalt materials. With funding from the Michigan Department of Environmental Quality, they have constructed test sections of road in two Michigan counties to monitor field performance.

Another possible solution is asphalt derived from biomass. You’s team used bio oil in asphalt and found it improved pavement performance. They’re also investigating nanomaterial-modified asphalt. “Soon we’ll have mix recipes to adapt to all environmental and waste supply streams,” he says.

The holy grail of energy storage—Solving the problems of lithium anodes

Samsung exploded phone
A damaged Samsung Galaxy Note 7 after its lithium battery caught fire. Photo Credit: Shawn L. Minter, Associated Press

State-of-the-art mechanical characterization of pure lithium metal, performed at submicron-length scales, provides signifcant physical insight into critical factors that limit the performance of next generation energy storage devices.

Erik Herbert, Michigan Tech
Erik Herbert, Materials Science & Engineering

Compared to competing technology platforms, a pure lithium anode potentially offers the highest possible level of volumetric and gravimetric energy density. Gradual loss of lithium over the cycle life of a battery prevents the full fruition of this energy technology.

Michigan Tech researchers Erik Herbert, Stephen Hackney, and their collaborators at Oak Ridge National Laboratory and the University of Michigan are investigating the behavior of a lithium anode accessed through, and protected by, polycrystalline superionic solid electrolytes. Their goals: Mitigate the loss of lithium; prevent dangerous side reactions; and enable safe, long-term, and high-rate cycling performance.

“We want to maintain efficient cycling of lithium in a battery over many cycles, something that’s never been done before,” says Herbert. “The fundamental challenge is figuring out how to maintain a coherent interface between the lithium anode and the solid electrolyte. Defects formed in the lithium during cycling determine the stability and resistivity of the interface. Once we see how that happens, it will reveal design rules necessary to successfully fabricate the solid electrolyte, and the battery packaging.”

The team is launching parallel efforts to address these issues. Herbert, for his part, wants to learn exactly how lithium is consumed on a nanoscale level, in real time. “We want to know why the interface becomes increasingly resistive with cycling, how the electrolyte eventually fails, how defects in the lithium migrate, agglomerate, or anneal with further cycling or time, and whether softer electrolytes can be used without incursion of metallic lithium into the electrolyte,” he says. “We also want to learn how processing and fabrication affect interface performance.”

“We want to maintain efficient cycling of lithium in a battery over many cycles, something that’s never been done before.”

Erik Herbert

polycrystalline lithium film
Surface of the polycrystalline lithium film, with over 100 residual impressions from targeted test sites

To answer these questions, Herbert conducts nano-indentation studies on vapor-deposited lithium films, various sintered solid electrolytes, and lithium films in fully functional solid-state batteries.

“The data from these experiments directly enable exam-ination of the complex coupling between lithium’s micro-structure, its defects, and its mechanical behavior,” says Herbert. “So far we’ve gained a better understanding of the mechanisms lithium utilizes to manage pressure (stress) as a function of strain, strain rate, temperature, defect structure, microstructural length scale, and in-operando cycling of the battery.”

Atomic resolution image of a spinel intergrowth lithium ion battery electrode particle and associated convergent beam electron diffraction pattern. The ordered dots all over the black triangle (the particle) are atomic columns, with a convergent beam electron diffraction pattern in white at the top. These results were obtained with the FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM) recently commissioned by Michigan Tech.
These results were obtained with the FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM) recently commissioned by Michigan Tech.

Atomic resolution image of a spinel intergrowth lithium ion battery electrode particle and associated convergent beam electron diffraction pattern. The ordered dots all over the black triangle (the particle) are atomic columns, with a convergent beam electron diffraction pattern in white at the top.


Michigan Tech's FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM) positions Michigan Tech faculty on the leading edge of new imaging capability for structural and chemical analysis at the nano-scale.
Michigan Tech’s FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM)

Michigan Tech’s FEI 200kV Titan Themis Scanning Transmission Electron Microscope (S-TEM) positions Michigan Tech faculty on the leading edge of new imaging capability for structural and chemical analysis at the nano-scale.