Tag Archives: University of Houston (UH)

Transforming lithium-ion battery electrodes into wearable, fabric-based, flexible, and stretchable electrodes

There’s a long road before this technology can be commercialized but the news seems promising. From a July 26, 2023 University of Houston news release (also on EurekAlert) by Rashda Khan, Note: Links have been removed,

Most people already know and appreciate the capabilities of smart phones, now imagine the possibilities offered by smart spacesuits, uniforms and exercise clothes. The future of wearable technology just got a big boost thanks to a team of University of Houston researchers who designed, developed and delivered a successful prototype of a fully stretchable fabric-based lithium-ion battery.

The idea for this cutting-edge evolution of the lithium-ion battery came from the mind of Haleh Ardebili, Bill D. Cook Professor of Mechanical Engineering at UH. “As a big science fiction fan, I could envision a ‘science-fiction-esque future’ where our clothes are smart, interactive and powered,” she said. “It seemed a natural next step to create and integrate stretchable batteries with stretchable devices and clothing. Imagine folding or bending or stretching your laptop or phone in your pocket. Or using interactive sensors embedded in our clothes that monitor our health.”

Some of these ideas are already becoming a reality. However, like all electronics, they need power, which is where the stretchable and flexible batteries come in. A major bottleneck in the development of the next generation of electronics or wearable technology embedded in fabrics is that conventional batteries are generally rigid, which limits functionality of the items, and they use a liquid electrolyte, which raises safety concerns. The traditional organic liquid electrolytes are flammable and can lead to the possibility of the batteries catching fire or even exploding under certain conditions.

The key to the UH research team’s breakthrough lies in the researchers using conductive silver fabric as a platform and current collector.

“The weaved silver fabric was ideal for this since it mechanically deforms or stretches and still provides electrical conduction pathways necessary for the battery electrode to function well. The battery electrode must allow movement of both electrons and ions,” said Ardebili, who is the corresponding author of a paper detailing this research in the Extreme Mechanics Letters. The first author of the paper is Bahar Moradi Ghadi, a former doctoral student who based her dissertation on this research.

By transforming rigid lithium-ion battery electrodes into wearable, fabric-based, flexible, and stretchable electrodes, this technology opens up exciting possibilities by offering stable performance and safer properties for wearable devices and implantable biosensors.

How It All Started

The idea for stretchable batteries occurred to Ardebili several years ago.

“I was interested in understanding the fundamental science and mechanisms related to stretching an electrochemical cell and its components,” she said. “This was an unexplored field in science and engineering and a great area to investigate.”

The science of coupling effects of mechanical deformation and electrochemical performance is an important field and stretchable batteries provide a great vehicle for exploring the fundamental mechanisms.

Ardebili developed her ideas into grant proposals and won several key awards to support her work, including a five-year National Science Foundation CAREER Award in 2013, a New Investigator Award from the NASA Texas Space Center Grant Consortium in 2014 and an award from the US Army Research Lab (ARL) in 2017.

“Although we have created a prototype, we are still working on optimizing the battery design, materials and fabrication,” said Ardebili.

What Is Next

Ardebili is optimistic that the prototype for a stretchable fabric-based battery will pave the way for many types of applications such as smart space suits, consumer electronics embedded in garments that monitor people’s health and devices that interact with humans at various levels. There are many possible designs and applications for safe, light, flexible and stretchable batteries, but there is still some work to be done before they are available on the market.

“Commercial viability depends on many factors such as scaling up the manufacturability of the product, cost and other factors,” she said. “We are working toward those considerations and goals as we optimize and enhance our stretchable battery.”

Whether the stretchy batteries end up powering spacesuits or workout clothes or some other innovative application, Ardebili wants them to be reliable and safe. “My goal is to make sure the batteries are as safe as possible [emphasis mine],” she said.

I’m glad to see safety is mentioned since there have been issues with lithium-ion batteries bursting into flame. (My last piece on research into making lithium-ion batteries safer is a January 13, 2016 post. There’s a more recent piece in the IEEE’s Spectrum magazine, an August 23, 2018 article by Weiyang Li and Yi Cui)

Getting back to the latest, here’s a link to and a citation for the paper,

Stretchable fabric-based lithium-ion battery by Bahar Moradi Ghadi, Banafsheh Hekmatnia, Qiang Fu, and Haleh Ardebili. Extreme Mechanics Letters
Volume 61, June 2023, 102026 DOI: https://doi.org/10.1016/j.eml.2023.102026

This paper is behind a paywall.

Glucose-sensing contact lens invented by US and Korean researchers

Blood tests for glucose levels may one day be a feature of the past according to an Oct. 3, 2016 news item on ScienceDaily,

Blood testing is the standard option for checking glucose levels, but a new technology could allow non-invasive testing via a contact lens that samples glucose levels in tears.

“There’s no noninvasive method to do this,” said Wei-Chuan Shih, a researcher with the University of Houston [UH] who worked with colleagues at UH and in Korea to develop the project, described in the high-impact journal Advanced Materials. “It always requires a blood draw. This is unfortunately the state of the art.”

A Sept. 27, 2016 UH news release (also on EurekAlert) by Jeannie Kever, which originated the news item, describes the proposed technology,

… glucose is a good target for optical sensing, and especially for what is known as surface-enhanced Raman scattering spectroscopy [also known as surface-enhanced Raman scattering or surface-enhanced Raman spectroscopy, and SERS], said Shih, an associate professor of electrical and computer engineering whose lab, the NanoBioPhotonics Group, works on optical biosensing enabled by nanoplasmonics.

This is an alternative approach, in contrast to a Raman spectroscopy-based noninvasive glucose sensor Shih developed as a Ph.D. student at the Massachusetts Institute of Technology. He holds two patents for technologies related to directly probing skin tissue using laser light to extract information about glucose concentrations.

The paper describes the development of a tiny device, built from multiple layers of gold nanowires stacked on top of a gold film and produced using solvent-assisted nanotransfer printing, which optimized the use of surface-enhanced Raman scattering to take advantage of the technique’s ability to detect small molecular samples.

Surface-enhanced Raman scattering – named for Indian physicist C.V. Raman [Raman scattering; SERS history begins in 1973 according to its Wikipedia entry], who discovered the effect in 1928 – uses information about how light interacts with a material to determine properties of the molecules that make up the material.

The device enhances the sensing properties of the technique by creating “hot spots,” or narrow gaps within the nanostructure which intensified the Raman signal, the researchers said.

Researchers created the glucose sensing contact lens to demonstrate the versatility of the technology. The contact lens concept isn’t unheard of – Google has submitted a patent for a multi-sensor contact lens, which the company says can also detect glucose levels in tears – but the researchers say this technology would also have a number of other applications.

“It should be noted that glucose is present not only in the blood but also in tears, and thus accurate monitoring of the glucose level in human tears by employing a contact-lens-type sensor can be an alternative approach for noninvasive glucose monitoring,” the researchers wrote.

“Everyone knows tears have a lot to mine,” Shih said. “The question is, whether you have a detector that is capable of mining it, and how significant is it for real diagnostics.”

In addition to Shih, authors on the paper include Yeon Sik Jung, Jae Won Jeong and Kwang-Min Baek, all with the Korea Advanced Institute of Science and Technology; Seung Yong Lee of the Korea Institute of Science and Technology, and Md Masud Parvez Arnob of UH.

Although non-invasive glucose sensing is just one potential application of the technology, Shih said it provided a good way to prove the technology. “It’s one of the grand challenges to be solved,” he said. “It’s a needle in a haystack challenge.”

Scientists know that glucose is present in tears, but Shih said how tear glucose levels correlate with blood glucose levels hasn’t been established. The more important finding, he said, is that the structure is an effective mechanism for using surface-enhanced Raman scattering spectroscopy.

Although traditional nanofabrication techniques rely on a hard substrate – usually glass or a silicon wafer – Shih said researchers wanted a flexible nanostructure, which would be more suited to wearable electronics. The layered nanoarray was produced on a hard substrate but lifted off and printed onto a soft contact, he said.

Here’s a link to and a citation for the paper,

Wafer Scale Phase-Engineered 1T- and 2H-MoSe2/Mo Core–Shell 3D-Hierarchical Nanostructures toward Efficient Electrocatalytic Hydrogen Evolution Reaction by Yindong Qu, Henry Medina, Sheng-Wen Wang, Yi-Chung Wang, Chia-Wei Chen, Teng-Yu Su, Arumugam Manikandan, Kuangye Wang, Yu-Chuan Shih, Je-Wei Chang, Hao-Chung Kuo, Chi-Yung Lee, Shih-Yuan Lu, Guozhen Shen, Zhiming M. Wang, and Yu-Lun Chueh. Advanced Materials DOI: 10.1002/adma.201602697 Version of Record online: 26 SEP 2016

© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

This paper is behind a paywall.

Université de Montréal (Canada) collaborates with University of Houston (US) for a new theory and better solar cells

Solar cell efficiency is not good as researchers from  l’Université de Montréal (UdeM, located in Quebec, Canada) and the University of Houston (UH, located Texas, US) note in a Jan. 29, 2014 joint UH/UdeM news release written by Lisa Merkl (UH) on EurekAlert,

“Scientists don’t fully understand what is going on inside the materials that make up solar cells. We were trying to get at the fundamental photochemistry or photophysics that describes how these cells work,” Bittner said [Eric Bittner, a John and Rebecca Moores Professor of Chemistry and Physics in UH’s College of Natural Sciences and Mathematics,].

Solar cells are made out of organic semiconductors – typically blends of materials. However, solar cells made of these materials have about 3 percent efficiency. Bittner added that the newer materials, the fullerene/polymer blends, only reach about 10 percent efficiency.

“There is a theoretical limit for the efficiency of the ideal solar cell – the Shockley-Queisser limit. The theory we published describes how we might be able to get above this theoretical limit by taking advantage of quantum mechanical effects,” Bittner said. “By understanding these effects and making use of them in the design of a solar cell, we believe you can improve efficiency.”

Silva [Carlos Silva, an associate professor at the Université de Montréal and Canada Research Chair in Organic Semiconductor Materials] added, “In polymeric semiconductors, where plastics form the active layer of solar cells, the electronic structure of the material is intimately correlated with the vibrational motion within the polymer chain. Quantum-mechanical effects due to such vibrational-electron coupling give rise to a plethora of interesting physical processes that can be controlled to optimize solar cell efficiencies by designing materials that best exploit them.”

Unfortunately, there’s no more information about this model other than this (from the news release),

“Our theoretical model accomplishes things that you can’t get from a molecular model,” he [Bittner] said. “It is mostly a mathematical model that allows us to look at a much larger system with thousands of molecules. You can’t do ordinary quantum chemistry calculations on a system of that size.”

The calculations have prompted a series of new experiments by Silva’s group to probe the outcomes predicted by their model.

Bittner and Silva’s next steps involve collaborations with researchers who are experts in making the polymers and fabricating solar cells.

Here’s a link to and a citation for the paper,

Noise-induced quantum coherence drives photo-carrier generation dynamics at polymeric semiconductor heterojunctions by Eric R. Bittner & Carlos Silva. Nature Communications 5, Article number: 3119 doi:10.1038/ncomms4119 Published 29 January 2014

This article is behind a paywall although you can get a free preview via ReadCube Access.