News Archive 2021

News Articles

Physicist, Non-Profits Build and Test Air Purifiers that Removes COVID Particles

Reference: University of Arkansas Newswire — Sept 16, 2021

 

With simple, inexpensive supplies available at any general department or home improvement store, Hugh Churchill is building and testing portable air filters that help remove infectious airborne particles — including the respiratory droplets that carry coronavirus — from indoor spaces.

And he wants to show you how to build one yourself. All you need is duct tape, a basic box fan and commercially available air filters.

“While masks and vaccines are polarizing topics,” said Churchill, associate professor of physics, “there shouldn’t be anything controversial about clean air. These devices facilitate that. They provide an additional layer of protection that could be widely deployed to make our K-12 and university indoor spaces healthier during this wave of the pandemic. And they’re easy and inexpensive to build. My 9-year-old built one.”

Churchill, a member of the Arkansas Research Alliance Academy of Scholars and Fellows, studies condensed matter and quantum materials to develop or improve devices that help people and the environment. For example, researchers in his lab focus on spiraling chains of selenium and tellurium, two materials that, when used in nanowires, show promise in the next generation of digital technology, solar energy and quantum computing.

But this project and others have taken a temporary back seat to fighting COVID-19. For several weeks, Churchill has been working with U of A Facilities Management and the Arkansas Research Alliance to build a prototype of a simple box-fan filter that helps purify room air and test its performance.

“Improving filtration and ventilation in classrooms is a common recommendation to help fight the spread of COVID-19 and improve indoor air quality,” Churchill said. “There are commercial products that do this, but they can be cost-prohibitive. Our teachers and school districts have worked extremely hard and used many tools to keep our kids’ classrooms safe. This is one more tool to help them.”

PURIFYING AIR – HOW IT WORKS

Within the facilities and HVAC communities, there is a burgeoning movement nationwide to make indoor spaces as safe as possible. Relying on open-source and simple do-it-yourself designs by air-quality experts, citizen scientists and amateurs have joined this movement, fashioning their own homemade air purifiers.

Churchill brings a higher level of scientific credibility to the fabrication and testing of an essentially homemade box-fan filter. Part of his work with nanoscale electronic devices focuses on eliminating air particles, which can ruin devices. And, for 15 years, Churchill has worked in so-called “clean rooms” with extremely well-filtered air.

Churchill measures the success of the purifier with a particle counter, which helps researchers in his lab evaluate different types of filters. They also have special microscopes that enable them to see microscopic holes in filter material, holes that particles can pass through. For example, the filter they tested from one popular manufacturer had many such holes. Consequently, its particle removal efficiency was measured to be much lower than expected.

Churchill’s purifier is an augmented version of the “Corsi-Rosenthal cube,” a concept and design by Richard Corsi at Portland State University. Corsi is an internationally recognized expert on indoor air quality. Four or five filters with a minimum efficiency reporting value — known as “MERV” in the HVAC industry — of 13 and a basic fan form the sides of the cube. The corners and seams are sealed and held together with duct tape. Using multiple filters means clean air delivery rate is higher and the cube will last longer, possibly six months.

With help from HVAC expert Ben Doudna in Facilities Management, Churchill measured the particle filtration efficiency and air flow of the filters. These cubes can deliver an estimated clean-air delivery rate of about 470 cubic feet per minute, which means one cube could produce four air changes per hour for a 900-square-foot classroom with 8-foot ceilings. This is within the range of four to six air changes per hour recommended to reduce airborne transmission.

CORONAVIRUS AND THE SCIENCE BEHIND AIR FILTERS

Vaccinations and wearing a mask are the surest ways to prevent the spread of coronavirus, but the Centers for Disease Control and Prevention also recommends portable air filters as a method to remove infectious airborne particles from indoor spaces. This is especially important for higher risk settings such as health clinics, vaccination and medical testing locations, and schools, where virtually half the population cannot yet receive vaccinations.

The particle size of SARS-CoV-2, the virus that causes COVID-19, is about 0.1 micrometer, or one-tenth of one micrometer. To get an idea how small this is, one micrometer is 100 times smaller than the thickness of a sheet of paper. However, when viral particles are exhaled during talking, singing, breathing and coughing, they are trapped in larger particles, some that quickly drop out of the air and others that remain suspended in room air for minutes to hours.

According to the CDC, high efficiency particulate air (HEPA) filters are 99.97 percent efficient at capturing human-generated viral particles associated with SARS-CoV-2. Portable filtration units that combine a HEPA filter with a powered fan system do not bring in outdoor air for dilution, but they can clean air within spaces to reduce the concentration of airborne particulates.

Commercial HEPA-based fans cost about $250. Churchill said their purifier would cost less than $100 for a box fan, four filters and duct tape. A single-filter design suitable for smaller rooms can also be made for half the price. He emphasized that recently the U.S. Department of Education clarified that costs for air-quality improvements for elementary, secondary and higher education classrooms can be covered by the American Rescue Plan.

“The purifier tested by Hugh provides a cost-effective way, supported by data, to immediately address one of the most pressing air quality needs schools face, that of addressing COVID-19,” said Stan Green, owner of Clear Energy, an energy performance contractor that helps schools with HVAC and energy efficiency projects. “Funding is always a factor in addressing the many aspects of indoor air quality, but this innovative approach lets schools generate immediate reductions in the presence of SARS-CoV-2 particles at a very low cost. Poorly ventilated spaces will benefit tremendously, but even well-ventilated spaces will see an improvement.”

COLLABORATION WITH ARKANSAS NON-PROFITS

Churchill is an Arkansas Research Alliance Academy Fellow. The ARA Academy represents a community of 32 strategic research leaders across five universities and the state’s only national lab. Douglas Hutchings, director of the ARA Academy, is working with Churchill to develop web-based resources that explain the science behind the purifier and provide instructions for making them.

These resources are available at CleanARAir, where Churchill and Hutchings also provide links to shopping carts on Walmart.com and Amazon, so teachers and parents can purchase parts and kits. The site provides data on filter efficiency.

Churchill and Hutchings have developed educational resources related to the design and function of the purifier. Also available at CleanARAir, these resources include lesson plans in math, science and English/language arts, ranging from basic literacy to advanced calculus. For example, for the math and science components of the project, there are several opportunities to measure flow rates, particle counts and proportional relationships. Students can also experiment with a wide range of designs. Curriculum kits enable students to develop hypotheses and rapidly test them to compare modeled data versus measurement data.

“The DIY approach creates inquiry-based learning opportunities and enables young minds to engage with their environment,” Hutchings said.

Innovate Arkansas, a state-sponsored initiative to help technology entrepreneurs create viable companies, has provided support in developing the supply chain necessary to deploy thousands of kits. The Northwest Arkansas Council is facilitating discussions with local business and philanthropic leaders to provide wholesale prices and get kits to teachers quickly. Finally, Startup Junkie, a non-profit organization that offers consulting services to entrepreneurs, has helped the researchers with a system to accept tax-deductible donations to help get purifiers in the hands of teachers and schools.

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

$18M NSF Grant to Build National Semiconductor Fabrication Facility

Reference: University of Arkansas Newswire — Oct 06, 2021

Engineering researchers led by Distinguished Professor Alan Mantooth have received $17.87 million from the National Science Foundation to build and operate a national silicon carbide research and fabrication facility at the U of A.

“The national impact of having a fabrication facility such as this is enormous,” Mantooth said. “The country that leads the world in advancing silicon carbide semiconductor design and fabrication will also lead the race to market nearly all new game-changing technologies, including those used by the military, as well as general electronic devices that are essential to our economy.”

The unique and open-access facility at the U of A will fill a void in U.S. production of integrated circuits made with silicon carbide, a powerful semiconductor well suited for higher temperature environments. Silicon carbide has been studied for a long time, but until recently efforts to use it as a fully developed semiconductor have been stunted by the unavailability of high-quality silicon carbide wafers. Currently, all silicon carbide fabrication facilities in the U.S. are for internal use only, and U.S. research and development of silicon carbide integrated circuits relies on international fabrication.

The U of A facility will provide domestic opportunities for prototyping, proof-of-principle demonstrations and device design. It will be the only openly accessible fabrication facility of its kind in the U.S., meaning its facilities and services will be available to external researchers.

The NSF funding will pay for infrastructure, equipment, technology installation and enhancements to current facilities to accommodate new equipment. The funding will also cover three full-time staff members, a post-doctoral researcher for four years and miscellaneous funds for set up and operating equipment.

Mantooth and other U of A electrical engineering researchers have decades of experience working with silicon carbide. They are one of only a few university research groups capable of developing integrated circuits with the powerful semiconductor. Combining this expertise with cutting-edge equipment and infrastructure will enable the production of superior integrated circuits for lighter and faster electronic systems, which will also be more energy efficient and heat resistant.

For many years, integrated circuits for most electronics devices have been made with silicon only. Silicon carbide is transforming the power electronics industry with its superior physical properties — an exceptionally strong physical bond providing high mechanical, chemical and thermal stability. Its wide band gap — the movement of electrons and photons within energy bands — and high thermal stability also allow silicon carbide-based devices to function at extreme temperatures.

The facility will provide integrated circuits, sensors and devices for military and industrial applications such as solar inverters, electronics for cars – both electric and gas-powered – and systems used in heavy transportation and construction equipment, such as bulldozers. Electronics developed at the facility will also enable systems used in geothermal and space exploration.

The facility will train the next generation of semiconductor researchers and engineers who can work in both the silicon and silicon carbide semiconductor industries. Students at all degree levels will be given research opportunities and be exposed to a high-need area of science and technology. The research will also engage underrepresented students in this new and burgeoning area of electronics.

Co-principal-investigators on this project are Greg Salamo, Distinguished Professor of physics, Zhong Chen, associate professor of electrical engineering, Shannon Davis, business and operations manager in the Department of Electrical Engineering, and John Ransom, director of silicon carbide technology at X-FAB in Lubbock, Texas.

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

NIH Grant Will Further Researcher’s Work Detecting Breast Cancer

Reference: University of Arkansas Newswire — Oct 07, 2021

Electrical engineering professor Magda El-Shenawee’s effort to develop a more accurate and less-invasive method for detecting breast cancer will benefit from a $424,545 grant from the National Institutes of Health.

El-Shenawee works with pulsed, terahertz imaging, a type of electromagnetic radiation technology that produces high-quality images of biological tissue down to roughly 80 micrometers. The method scatters fewer waves than radiography, which enables deeper imaging into the tissue.

Terahertz imaging shows great promise as an alternative method for helping clinicians determine whether all cancerous tissue was removed during and immediately following a lumpectomy.

Standard breast cancer imaging techniques such as radiography and computed tomography, or CT scan, do not always provide a clear assessment of breast tissue on the margins of a tumor. This is especially important during a lumpectomy, which is the removal of cancerous breast tissue while trying to preserve healthy tissue surrounding it. Without an accurate picture of the margins between the tumor and healthy tissue, surgeons cannot be sure they removed all cancerous tissue.

This problem leads to a high rate — greater than 30 percent — of additional surgery. The need for an immediate imaging technology is especially critical at small hospitals and outpatient clinics that do not have access to an on-site pathology laboratory that could provide immediate results.

“Our pre-clinical models showed strong differentiation between cancerous and fatty tissues,” El-Shenawee said, “but the more clinically relevant differentiation between cancerous and healthy, non-fatty tissue remains challenging. To build upon the successes of our previous work and improve the sensitivity of terahertz imaging to detect cancer at the surgical margins, we have identified areas where we can make significant improvements.”

El-Shenawee’s research team, including Narasimhan Rajaram, associate professor of biomedical engineering, and Jingxian Wu, professor of electrical engineering, in addition to graduate students, will re-design instrumentation to develop more sensitive wave polarization. In this new approach, all four polarizations of waves will be incorporated to increase the spatial and spectral information about different types of tumor tissues.

The researchers will test the system on animal models with breast cancer and try to improve the accuracy of detection algorithms by combining spatial information embedded in the images with spatial statistics.

“We anticipate that the new approach will increase the image contrast between cancerous and healthy adjacent tissues, leading to better differentiation and classification of cancer on the tumor margins,” El-Shenawee said. “The success of this approach should allow us to expand our work and move toward clinical trials.”

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

$4.4 Million Grant to Build Prototype of Next-Gen Night Vision Technology

Reference: University of Arkansas Newswire — Oct 12, 2021

FAYETTEVILLE, Ark. – University of Arkansas researchers received a $4.4 million award from the U.S. Office of Naval Research to develop the next generation of infrared sensors used in night vision technology.

The three U of A researchers — electrical engineering professor Shui-Qing “Fisher” Yu, Distinguished Professor Greg Salamo, and Jin Hu, assistant professor of physics — will collaborate with the Navy Surface Warfare Research Center, Crane Division, and Arktonics, a local company. Together, they will use the semiconductor silicon germanium tin in designing and building the prototype of a superior and less-expensive infrared camera. The military uses infrared imaging technologies for night vision technology.

The grant will pay for specially designed equipment that will help the team develop the infrared imaging sensor array made of silicon germanium tin. The team will then integrate this array with a complementary metal oxide semiconductor, known as CMOS, on the same chip. CMOS technology is used for making integrated-circuit chips for microprocessors, controllers and other digital and analog circuits, including image sensors. The combination is more effective at harnessing ambient light, an essential element in night vision technology.

Current technologies rely on semiconducting alloys such as mercury cadmium telluride and other material-based photodetectors. These alloys have several limitations, including a complex and expensive manufacturing process, low production yield and poor uniformity over large areas. These limitations negatively affect wide-range infrared visibility, especially in areas with poor environmental conditions, such as sandy or hazy environments. These technologies also cannot integrate an infrared camera and other necessary electronics on the same chip, which increases cost and decreases reliability, efficiency and speed.

By more efficiently harnessing light, silicon germanium tin on silicon substrates is potentially a better solution. Yu has worked with silicon germanium tin for more than a decade. In 2016, he and colleagues reported the fabrication of a first-generation, “optically pumped” laser, meaning the material was injected with light, similar to an injection of electrical current. Yu was also the first to report an “electrical excited” germanium tin laser.

Using molecular beam epitaxy, Salamo has been growing semiconductor nanostructures for more than 20 years. He is well known for his work on quantum wells, dots and wires. Meanwhile, Hu has developed and fabricated new quantum materials and investigated their novel quantum properties.

The researchers hosted a Zoom meeting on Sept. 21 to kick off the project. The meeting was attended by U.S. Rep. Steve Womack, who helped secure funding for the research.

“I’m extremely proud of the collaboration between the University of Arkansas and the Navy to develop next-generation night vision sensor technology,” Womack said. “This world-class research will produce a prototype that will surpass current technology and increase military capabilities. It will also drive new, high-tech economic opportunities for our region and state. Ingenuity is opening doors to the future, and I will continue to support these efforts in Congress.”

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

Site Preparation Begins for Future I3R Facility

Reference: University of Arkansas Newswire — Oct 15, 2021

Site preparation has begun for the future Institute for Integrative and Innovative Research (I3R) Center, the U of A’s newest cross-disciplinary research facility.

This phase of work, officially called the Enabling Phase, will take place around the Nanoscience building and in Lot 71. Most of the construction is focused on adding utilities for the future institute and will include extending existing utility tunnels, extending electrical services for both the Nanoscience and new I3R buildings, providing chilled water to the site and clearing some of the existing utilities. The enabling phase will conclude with minor landscaping work prior to the official start of construction on the I3R facility.

Individuals who park in lot 71 will be affected by this project beginning with reduced parking followed by a full lot closure after the first of the year. Transit and Parking has already notified permit holders and provided options for alternative parking arrangements. Additional reminders will be sent to permit holders prior to the lot closing.

Occupants of the Nanoscience building are likely to notice a few impacts including noise and vibrations during the work. The work will also require some brief, scheduled power and hydronic outages, which will be coordinated to help minimize disruption.

Information regarding the official groundbreaking for the new I3R facility will be provided at a later date.

This phase of site work is tentatively scheduled to be completed this spring. Updates for the new I3R facility and other campus projects may be found on the Facilities Management website.

Institute for Integrative and Innovative Research

Funded by a grant from the Walton Family Charitable Support Foundation, the new institute will provide the campus with cross-disciplinary research capabilities and improved resources for U of A researchers. The facility will focus on five areas that fall within the university’s Signature Research Areas: food and technology, data science, materials science and engineering, bioscience and bioengineering research in metabolism and integrative systems neuroscience. The I3R building is tentatively scheduled to open in 2024.

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

Army Grants to Bolster Unique New Semiconductor Fabrication Facility

Reference: University of Arkansas Newswire — Oct 28, 2021

More than $5 million in total funding from the Army Research Office and the Army Research Laboratory will go toward a unique silicon carbide semiconductor fabrication facility at the U of A.

The grants — $4.5 million from the Army Research Office and $900,000 from the Army Research Laboratory — come on the heels of an $18 million grant from the National Science Foundation to fund construction and operation of the unique national fabrication facility.

Alan Mantooth, Distinguished Professor of electrical engineering, is principal investigator for both grants.

The Army Research Office grant will be used for equipment, and the Army Research Laboratory grant for student and staff compensation, tuition and materials for supporting collaborative research activities with the Army Research Lab.

Combining cutting-edge equipment and infrastructure with a core of research experts focused on silicon carbide semiconductor devices, sensors and integrated circuits, the fabrication facility will develop new electronics to address areas of national defense. Researchers will fabricate superior integrated circuits for compact and robust electronic devices for branches of the U.S. military. The devices will also be more energy efficient and heat resistant.

The facility will also train the next generation of semiconductor researchers and engineers who can work in both the silicon and silicon carbide semiconductor industries. Students at all degree levels will be given research opportunities and be exposed to a high-need area of science and technology. The research will engage underrepresented students in this new and burgeoning area of electronics.

With now decades of experience working with silicon carbide, Mantooth will lead a team that will acquire, install and integrate cutting-edge equipment for the purpose of building a low-volume prototyping facility to produce silicon-carbide integrated circuits.

In addition to Mantooth, researchers on this project include Greg Salamo, Distinguished Professor of physics; Zhong Chen, associate professor of electrical engineering; and Shannon Davis, business and operations manager in the Department of Electrical Engineering.

About the University of Arkansas: As Arkansas’ flagship institution, the U of A provides an internationally competitive education in more than 200 academic programs. Founded in 1871, the U of A contributes more than $2.2 billion to Arkansas’ economy through the teaching of new knowledge and skills, entrepreneurship and job development, discovery through research and creative activity while also providing training for professional disciplines. The Carnegie Foundation classifies the U of A among the top 3% of U.S. colleges and universities with the highest level of research activity. U.S. News & World Report ranks the U of A among the top public universities in the nation. See how the U of A works to build a better world at Arkansas Research News.

New ‘Short Talks’ Features Hugh Churchill Discussing the MonArk Quantum Foundry

Reference: University of Arkansas Newswire — Dec 02, 2021

This month’s Short Talks From the Hill, a research podcast of the U of A, features Hugh Churchill, associate professor of physics in the Fulbright College of Arts and Sciences.

Earlier this year, Churchill, Salvador Barraza-Lopez and several of their colleagues at the U of A and Montana State University received a $20 million grant from the National Science Foundation to establish the MonArk NSF Quantum Foundry. The foundry will accelerate the development of quantum materials and devices.

“What we want to do in the MonArk NSF Quantum Foundry is use robots and artificial intelligence to accelerate that process of creating materials and making devices,” Churchill says in the podcast. “A big part of our effort is that we hope to become, really, a national resource that researchers from all over can turn to, to have materials and devices made for them and help accelerate progress in our entire research community.”

Churchill, a native Arkansan from Conway, also discusses a project to build and test — and show the general public how to build — a basic, portable air filter that removes infectious airborne particles from indoor spaces. These particles include the respiratory droplets that carry coronavirus.

“The virus can spread on tiny particles that can float in the air for as long as hours,” Churchill says. “And so there are various ways that you could deal with that, but one that’s relatively easy to implement is to set up an air purifier in a room that will just remove those particles from the air as they are generated.”

To listen to Churchill discuss these projects, click the link above or go to Arkansas Research, the home of science and research news at the University of Arkansas.

Short Talks From the Hill highlights research and scholarly work at the University of Arkansas. Each segment features a university researcher discussing their work. Previous podcasts can be found at the link above or by visiting arkansasresearch.uark.edu.

Thank you for listening!