As the summer heat intensifies, with temperatures sometimes soaring to triple digits, the question of which fabrics are best for staying cool becomes particularly relevant. Sundaresan Jayaraman, a professor in Georgia Tech’s School of Materials Science and Engineering, offers insights into the properties of various fabrics and why some are more effective than others in hot, humid conditions.

Jayaraman, a renowned expert in fibers, polymers, and textiles, recognizes linen as the best fabric for hot and humid conditions. He explains that linen's effectiveness lies in its superior moisture management properties. The fiber structure of linen allows it to absorb moisture quickly and then transport it away from the body. This is due to linen's high moisture regain capacity, which means it can absorb a significant amount of moisture without feeling damp.

“The moisture vapor transport rate for linen is much greater than that for cotton or polyester,” he explained. Additionally, linen's bending rigidity prevents it from clinging to the body, allowing for better air circulation.

Cotton is another popular fabric for summer, known for its softness and breathability. However, Jayaraman points out that while cotton effectively absorbs moisture, it tends to retain it longer than linen, making it feel clammy in extreme heat. Cotton's moisture vapor transmission rate is lower than linen’s, meaning it doesn't dry as quickly.

The structure of cotton fibers, which are ribbon-like and can trap more water, also affects cotton’s performance. While it’s more prone to sticking to the body due to its lower bending rigidity, cotton is generally comfortable for less humid conditions or for shorter durations in the heat.

While polyester may not be the first fabric that comes to mind for summer, its performance can be significantly enhanced with chemical treatments. Dri-FIT technology, for instance, improves polyester’s moisture-wicking properties, making it a popular choice for athletic wear.

“Regular polyester is terrible when it comes to moisture absorption,” admitted Jayaraman. “But Dri-FIT polyester doesn’t feel clammy and is very comfortable for being physically active in the summer months.”

While functionality is crucial, aesthetics also play a role in fabric choice for the summer. Linen, despite its excellent cooling properties, is prone to wrinkling and may not drape as elegantly as cotton or treated polyester. Jayaraman notes that linen's natural stiffness, which contributes to its cooling benefits, also leads to its tendency to wrinkle. He says, “For a crisp appearance, linen garments often require ironing before wear.” For those prioritizing appearance, cotton offers a softer drape and a smoother look, albeit with slightly less cooling efficiency.

Adoptive T-cell therapy has revolutionized medicine. A patient’s T-cells — a type of white blood cell that is part of the body’s immune system — are extracted and modified in a lab and then infused back into the body, to seek and destroy infection, or cancer cells. 

Now Georgia Tech bioengineer Ankur Singh and his research team have developed a method to improve this pioneering immunotherapy. 

Their solution involves using nanowires to deliver therapeutic miRNA to T-cells. This new modification process retains the cells’ naïve state, which means they’ll be even better disease fighters when they’re infused back into a patient.

“By delivering miRNA in naïve T cells, we have basically prepared an infantry, ready to deploy,” Singh said. “And when these naïve cells are stimulated and activated in the presence of disease, it’s like they’ve been converted into samurais.”

Lean and Mean

Currently in adoptive T-cell therapy, the cells become stimulated and preactivated in the lab when they are modified, losing their naïve state. Singh’s new technique overcomes this limitation. The approach is described in a new study published in the journal Nature Nanotechnology.

“Naïve T-cells are more useful for immunotherapy because they have not yet been preactivated, which means they can be more easily manipulated to adopt desired therapeutic functions,” said Singh, the Carl Ring Family Professor in the Woodruff School of Mechanical Engineering and the Wallace H. Coulter Department of Biomedical Engineering. 

The raw recruits of the immune system, naïve T-cells are white blood cells that haven’t been tested in battle yet. But these cellular recruits are robust, impressionable, and adaptable — ready and eager for programming.

“This process creates a well-programmed naïve T-cell ideal for enhancing immune responses against specific targets, such as tumors or pathogens,” said Singh.

The precise programming naïve T-cells receive sets the foundational stage for a more successful disease fighting future, as compared to preactivated cells.

Knitting, the age-old craft of looping and stitching natural fibers into fabrics, has received renewed attention for its potential applications in advanced manufacturing. Far beyond their use for garments, knitted textiles are ideal for designing and fabricating emerging technologies like wearable electronics or soft robotics — structures that need to move and bend. 

Knitting transforms one-dimensional yarn into two-dimensional fabrics that are flexible, durable, and highly customizable in shape and elasticity. But to create smart textile design techniques that engineers can use, understanding the mechanics behind knitted materials is crucial. 

Physicists from the Georgia Institute of Technology have taken the technical know-how of knitting and added mathematical backing to it. In a study led by Elisabetta Matsumoto, associate professor in the School of Physics, and Krishma Singal, a graduate researcher in Matsumoto’s lab, the team used experiments and simulations to quantify and predict how knit fabric response can be programmed. By establishing a mathematical theory of knitted materials, the researchers hope that knitting — and textiles in general — can be incorporated into more engineering applications.

Their research paper, “Programming Mechanics in Knitted Materials, Stitch by Stitch,” was published in the journal Nature Communications. 

“For centuries, hand knitters have used different types of stitches and stitch combinations to specify the geometry and ‘stretchiness’ of garments, and much of the technical knowledge surrounding knitting has been handed down by word of mouth,” said Matsumoto.

But while knitting has often been dismissed as unskilled, poorly paid “women’s work,” the properties of knits can be more complex than traditional engineering materials like rubbers or metals. 

For this project, the team wanted to decode the underlying principles that direct the elastic behavior of knitted fabrics. These principles are governed by the nuanced interplay of stitch patterns, geometry, and yarn topology — the undercrossings or overcrossings in a knot or stitch. "A lot of yarn isn’t very stretchy, yet once knit into a fabric, the fabric exhibits emergent elastic behavior," Singal said. 

“Experienced knitters can identify which fabrics are stretchier than others and have an intuition for its best application,” she added. “But by understanding how these fabrics can be programmed and how they behave, we can expand knitting’s application into a variety of fields beyond clothing.”

Through a combination of experiments and simulations, Matsumoto and Singal explored the relationships among yarn manipulation, stitch patterns, and fabric elasticity, and how these factors work together to affect bulk fabric behavior. They began with physical yarn and fabric stretching experiments to identify main parameters, such as how bendable or fluffy the yarn is, and the length and radius of yarn in a given stitch. 

They then used the experiment results to design simulations to examine the yarn inside a stitch, similar to an X-ray. It is difficult to see inside stitches during the physical measurements, so the simulations are used to see what parts of the yarn have interacted with other parts. The simulations are used to recreate the physical measurements as accurately as possible.

Through these experiments and simulations, Singal and Matsumoto showed the profound impact that design variations can have on fabric response and uncovered the remarkable programmability of knitting. "We discovered that by using simple adjustments in how you design a fabric pattern, you can change how stretchy or stiff the bulk fabric is," Singal said. "How the yarn is manipulated, what stitches are formed, and how the stitches are patterned completely alter the response of the final fabric."

Matsumoto envisions that the insights gleaned from their research will enable knitted textile design to become more commonly used in manufacturing and product design. Their discovery that simple stitch patterning can alter a fabric’s elasticity points to knitting’s potential for cutting-edge interactive technologies like soft robotics, wearables, and haptics.

“We think of knitting as an additive manufacturing technique — like 3D printing, and you can change the material properties just by picking the right stitch pattern,” Singal said.

Matsumoto and Singal plan to push the boundaries of knitted fabric science even further, as there are still numerous questions about knitted fabrics to be answered. 

"Textiles are ubiquitous and we use them everywhere in our lives," Matsumoto said. "Right now, the hard part is that designing them for specific properties relies on having a lot of experience and technical intuition. We hope our research helps make textiles a versatile tool for engineers and scientists too."

Note: Sarah Gonzalez (Georgia Tech) and Michael Dimitriyev (Texas A&M) are also co-first authors of the study. 

Citation: Singal, K., Dimitriyev, M.S., Gonzalez, S.E. et al. Programming mechanics in knitted materials, stitch by stitch. Nat Commun 15, 2622 (2024). 

DOI: https://doi.org/10.1038/s41467-024-46498-z

Funding: Research Corporation for Science Advancement, National Science Foundation, and the Alfred P. Sloan Foundation 

Semiconductors make our world run, but the industry faces a turning point. For decades, computer chip efficiency has doubled every two years, but that progress is slowing. To complicate the problem further, global demand for semiconductors threatens to outpace the supply. The U.S. has the opportunity to meet the growing need for chips — both by increasing domestic manufacturing and building up the workforce, which is at its lowest in decades. To bolster semiconductor research and manufacturing, in 2022, Congress passed the $52.7 billion bipartisan CHIPS and Science Act that President Joe Biden signed into law. New paradigms and pioneers are needed to make these critical advances.

Georgia Tech is playing a significant role in creating the next generation of chips, as the Institute is especially well positioned to innovate in the semiconductor field. All areas of the semiconductor stack — the components that build a chip, from hardware to artificial intelligence — are studied at Tech, and collaboration among faculty is a hallmark of its research enterprise. Such cooperation is necessary to build better chips, since they need to be reinvented in every layer of the stack.

Read the full story on GT Research News.

Georgia Tech has been selected as one of six universities globally to receive funding for the newly established Global Industrial Technology Cooperation Center. The announcement was made by the Ministry of Trade, Industry, and Energy in South Korea during the Global Open Innovation Strategy Meeting in April.

The KIAT-Georgia Tech Semiconductor Electronics Center will receive $1.8 million to establish a sustainable semiconductor electronics research partnership between Korean companies, researchers, and Georgia Tech. 

“I am thrilled to announce that we have secured funding to launch a groundbreaking collaboration between Georgia Tech’s world-class researchers and Korean companies,” said Hong Yeo, associate professor and Woodruff Faculty Fellow in the George W. Woodruff School of Mechanical Engineering and the Wallace H. Coulter Department of Biomedical Engineering. “This initiative will drive the development of cutting-edge technologies to advance semiconductor, sensors, and electronics research.”

Yeo will lead the center, and Michael Filler, interim executive director for the Institute of Electronics and Nanotechnology, and Muhannad Bakir, director of the 3D Advanced Packaging Research Center, will serve as co-PIs.

The center will focus on advancing semiconductor research, a critical area of technology that forms the backbone of modern electronics.

The Cooperation Center is a global technology collaboration platform designed to facilitate international joint research and development planning, partner matching, and local support for domestic researchers. The selection of Georgia Tech underscores the Institute’s leadership and expertise in the field of semiconductors.

The Biden-Harris Administration announced that the U.S. Department of Commerce and Absolics, an affiliate of the Korea-based SKC, have signed a non-binding preliminary memorandum of terms to provide up to $75 million in direct funding under the CHIPS and Science Act to help advance U.S. technology leadership. The proposed investment would support the construction of a 120,000 square-foot facility in Covington, Georgia and the development of substrates technology for use in semiconductor advanced packaging. Started through a collaboration with the 3D Packaging Research Center at Georgia Tech, Absolics’ project serves as an example of American lab-to-fab development and production.

"Glass-core packaging holds the promise to revolutionize the field of advanced packaging and impact major paradigms such as artificial intelligence, mm-wave/THz communication, and photonic connectivity," said Muhannad Bakir, Dan Fielder Professor in the School of Electrical and Computer Engineering and Director of the 3D Systems Packaging Research Center at Georgia Tech.  "We look forward to supporting Absolics in establishing a glass-core packaging facility in the State of Georgia through workforce development initiatives." 

Because of President Biden’s CHIPS and Science Act, this proposed investment would support over an estimated 1,000 construction jobs and approximately 200 manufacturing and R&D jobs in Covington and enhance innovation capacity at Georgia Institute of Technology, supporting the local semiconductor talent pipeline. 

The proposed investment with Absolics is the first proposed CHIPS investment in a commercial facility supporting the semiconductor supply chain by manufacturing a new advanced material.

Read the full story

An electrochemical process developed at Georgia Tech could offer new protection against bacterial infections without contributing to growing antibiotic resistance.

The approach capitalizes on the natural antibacterial properties of copper and creates incredibly small needle-like structures on the surface of stainless steel to kill harmful bacteria like E. coli and Staphylococcus. It’s convenient and inexpensive, and it could reduce the need for chemicals and antibiotics in hospitals, kitchens, and other settings where surface contamination can lead to serious illness.

It also could save lives: A global study of drug-resistant infections found they directly killed 1.27 million people in 2019 and contributed to nearly 5 million other deaths — making these infections one of the leading causes of death for every age group.

Researchers described the copper-stainless steel and its effectiveness May 20 in the journal Small.

Read the full story on the College of Engineering website.

The call from his mom is still vivid 20 years later. Moments this big and this devastating can define lives, and for Hong Yeo, today a Georgia Tech mechanical engineer, this call certainly did. Yeo was a 21-year-old in college studying car design when his mom called to tell him his father had died in his sleep. A heart attack claimed the life of the 49-year-old high school English teacher who had no history of heart trouble and no signs of his growing health threat. For the family, it was a crushing blow that altered each of their paths. 

“It was an uncertain time for all of us,” said Yeo. “This loss changed my focus.” 

For Yeo, thoughts and dreams of designing cars for Hyundai in Korea turned instead toward medicine. The shock of his father going from no signs of illness to gone forever developed into a quest for medical answers that might keep other families from experiencing the pain and loss his family did — or at least making it less likely to happen.  

Yeo’s own research and schooling in college pointed out a big problem when it comes to issues with sleep and how our bodies’ systems perform — data. He became determined to invent a way to give medical doctors better information that would allow them to spot a problem like his father’s before it became life-threatening. 

His answer: a type of wearable sleep data system. Now very close to being commercially available, Yeo’s device comes after years of working on the materials and electronics for an easy-to-wear, comfortable mask that can gather data about sleep over multiple days or even weeks, allowing doctors to catch sporadic heart problems or other issues. Different from some of the bulky devices with straps and cords currently available for at-home heart monitoring, it offers the bonuses of ease of use and comfort, ensuring little to no alteration to users’ bedtime routine or wear. This means researchers can collect data from sleep patterns that are as close to normal sleep as possible.  

“Most of the time now, gathering sleep data means the patient must come to a lab or hospital for sleep monitoring. Of course, it’s less comfortable than home, and the devices patients must wear make it even less so. Also, the process is expensive, so it’s rare to get multiple nights of data,” says Audrey Duarte, University of Texas human memory researcher.  

Duarte has been working with Yeo on this system for more than 10 years. She says there are so many mental and physical health outcomes tied to sleep that good, long-term data has the potential to have tremendous impact. 

“The results we’ve seen are incredibly encouraging, related to many things —from heart issues to areas I study more closely like memory and Alzheimer’s,” said Duarte. 

Yeo’s device may not have caught the arrhythmia that caused his father’s heart attack, but nights or weeks of data would have made effective medical intervention much more likely.  

Inspired by his own family’s loss, Yeo’s life’s work has become a tool of hope for others.  

When Amy Bonecutter-Leonard was a second-semester undergraduate at the Georgia Institute of Technology, she applied for a work-study job in the cleanroom at the Microelectronics Research Center (MiRC). There, she learned process techniques for making the same type of electronic chips used in cellphones.  

With this new knowledge, she could train and help other students with their research. At the time, Bonecutter-Leonard was a chemical engineering major with no plans to go into microelectronics. Working in the cleanroom changed that. 

“I fell in love with microelectronics through exposure to the research and development work performed in the cleanroom,” she said.  

What started as a student job led to her taking microelectronics classes — and eventually to a career in the field. “My work-study prepared me with hands-on technical skills I would have never learned from just being in a classroom,” she said. Now, Bonecutter-Leonard works as a microelectronics business chief engineer at defense contractor L3Harris Technologies.  

Her story is one of many from the Institute for Electronics and Nanotechnology (IEN, the successor to MiRC), which has been training students from kindergarten to graduate school to be leaders in the microelectronics and nanotechnology space. The goal of IEN’s outreach is to make nanotechnology and microelectronics — such as computer chips and sensors — as accessible as any other science. Ultimately, these efforts will build up the U.S. workforce in the field, ensuring the country remains at the forefront of the technology that powers Americans’ everyday lives. 
 

Building the Workforce 

Bolstering the number of workers in the microelectronics industry is imperative to keep the U.S. globally competitive. Right now, 40% of the industry's labor force is older than 50, with practitioners aging out of their careers at a pace new talent cannot match. Additionally, heavy educational barriers to entry, including required degrees and specialized training, prevent more people from pursuing careers in the field. Without dedicated efforts, the entire sector — and the nation — will fall behind.  

IEN is working to solve this pipeline problem.  

“With the national semiconductor workforce aging, it is important now more than ever that we educate the next generation to move into these jobs,” said Michael Filler, IEN’s interim executive director. “IEN is proud to support the semiconductor industry by providing students with the interdisciplinary skills and hands-on technical training essential for success in this fast-paced, global field.”  

Georgia Tech is uniquely positioned to lead this charge with its 28,500 square feet of academic cleanroom space, the largest in the Southeast and among the largest in the U.S. From micro-electro-mechanical systems to electronics fabrication, workers have 100 bays in which to conduct leading-edge research. These cleanrooms are also key teaching and training facilities. 

IEN invites anyone from around the world, whether affiliated with the Institute or not, to become a core user of the cleanroom facilities. The center also regularly hosts short courses for external partners — academic, industry, and government — in microfabrication and soft lithography for microfluidics. Over the past three years, more than 700 people went through new-user orientation, and 193 enrolled in the short courses. 

Teaching the Next Generation 

Making nanotechnology — of which microelectronics is an example — educationally accessible begins before college. Each semester, more than 800 K-12 students participate in IEN’s Introduction to Nanotechnology virtual lesson. Associate Director for Education and Outreach Mikkel Thomas begins his presentations by asking a simple question: What do you know about nanotechnology? 
 
“About 99% of the time, they say that’s what makes Ironman’s suit work,” said Thomas. “That means they’ve learned the wrong lesson — that nanotechnology is a futuristic tech and that you have to be as smart as Tony Stark to work in the field.  
 
“But most people interact with nanotechnology multiple times throughout their day, and they have no idea they're doing it.” 
 
Thomas also emphasizes there is a career path for everyone, even if they don’t plan to get a traditional four-year degree. Part of IEN’s workforce development initiative is to build up the entire pipeline from industry and research lab technicians at the certificate level to postdoctoral researchers. 
 
“It’s important for us to reach kids who don’t know what career options are available in nanotechnology,” Thomas said. “We want them to know that whatever they're interested in, there is a pathway for them.” 
 
Sixth- through eighth-grade students sparked by this conversation can attend Chip Camp, a three-day STEM summer camp sponsored by Micron. They begin with a day at IEN to learn about thin films, magic sands, ferrofluids, and measuring their height in nanometers. The rest of the camp features hands-on visits to the Materials Characterization Facility (MCF) and the IEN cleanroom, where they can try on the white “bunny suits” technicians wear in the lab. 
 
To further their reach, IEN’s workforce development team collaborates with teachers to bring nanotechnology into classrooms. During the summer, IEN offers the Research Experience for Teachers, a training program for public school and community college teachers to conduct nanotechnology research and learn how to incorporate it into their lessons. Middle school teachers have similar opportunities through the Nanoscience Summer Institute for Middle School Teachers.

Training the Workforce 

When these students get to a university like Georgia Tech, IEN hires them for work-study jobs like the one Bonecutter-Leonard had. The hands-on cleanroom training is also vital to graduate students pursuing advanced degrees. 
 
Katie Young earned her Ph.D. in materials science and engineering at Georgia Tech. Learning her way around the IEN cleanroom was essential for her graduate studies. 
 
“My dissertation research involved synthesizing two-dimensional materials — only a single atom thick — for permeation barriers,” she explained. “I often used the cleanroom’s vacuum systems to synthesize and process 2D materials.” Now a research scientist at the Georgia Tech Research Institute, Young still works in the cleanroom on semiconductor device fabrication, building prototype quantum and biological sensors. 
 
IEN opportunities are not limited to graduate research. Annually, about 150 Georgia Tech undergraduate students take microelectronics packaging and devices classes, with labs taught by IEN staff in the teaching cleanroom. These courses include Integrated Circuit Fabrication (ECE 4452), in which students learn to fabricate circuit elements, and the Science and Engineering of Microelectronic Fabrication (ChBE 4050/6050, open to graduate students as well), for students interested in semiconductor materials and fabrication. 

Students don’t need to enroll at Georgia Tech to benefit from training, courses, and other opportunities. IEN’s internship program provides technical college students with training to become microelectronics technicians, either through work in the Biocleanroom or in the MCF.

Empowering Future Innovators 

IEN also participates in the National Science Foundation Research Experiences for Undergraduates (REU), which provides opportunities for students from underrepresented groups or who attend schools without similar facilities. While enrolled at another university, John Mark Page was introduced to Georgia Tech’s cleanroom through an REU.  
 
“That was my first exposure to any facility of this kind, and it felt like I was looking at the future. Being in a facility that can fabricate devices at or near the atomic level — it was hard to fathom,” Page said. “I had never thought that participating in microelectronics and nanotechnology as a student, especially as an undergraduate, was something I could do.” 

As a result of his REU, Page transferred to Georgia Tech — he will graduate this summer with a bachelor’s degree in electrical engineering. He also completed a second REU at the University of North Carolina at Chapel Hill, worked as a student assistant in the IEN cleanroom, and participated in a Vertically Integrated Project (VIP), Chip Scale Power and Energy. 
 
“I was interested in the VIP because it allowed me to spend more time in the cleanroom, familiarizing myself with semiconductor fabrication methods and training on new fabrication equipment,” Page explained. His experiences inspired him to consider a future career in the semiconductor industry. 

“It wasn’t only the 10-week experience of the REU that made a lasting impact on me,” he said. “It was also the relationships formed with the people of IEN. The staff there are exceptional representatives of Georgia Tech, and they make IEN a tremendous asset to the future of microelectronics and nanotechnology in the U.S.” 

Biya Haile, an ECE Ph.D. student, had a similarly meaningful REU experience. Haile, whose research focuses on creating micro-electro-mechanical systems-based sensors (MEMS), described the REU as “immersive.” 

“The REU project enabled me to study chemical micro-sensor technologies, as well as state-of-the-art additive nano-manufacturing techniques, which has contributed to my research,” he said. “I feel lucky that my academic journey has entailed developing new technologies that use nanoscience to solve big problems.”  

While Haile is currently focused more on designing and testing rapid processes for fabricating MEMS-based devices, he still occasionally works in the cleanroom on fabrication. He plans to go into the microelectronics industry after graduating. 

The Path Ahead 

All of IEN’s training and educational offerings align with IEN’s mission to bolster and diversify the microelectronics workforce, according to George White, senior director of strategic partnerships for the Georgia Tech research enterprise. “IEN has been at the forefront of the CHIPS infrastructure buildout, particularly in the area of education and workforce development,” he noted.   

IEN’s efforts impact not just Atlanta but the entire country. Georgia Tech’s leadership in microelectronics research trains the innovators and practitioners of the future everywhere and ensures that America stays at the forefront of leading-edge technology. As demand increases for microelectronics, IEN is moving to meet it. 

Effective July 1, 2024, the Institute for Electronics and Nanotechnology and the Institute for Materials will evolve into the Institute for Matter and Systems (IMS). This strategic union aims to foster convergent research at Georgia Tech, focusing on the science, technology, and societal underpinnings of cutting-edge materials and devices. Eric Vogel will be the director of IMS, and Michael Filler will be the deputy director.