MXene nanomaterials enable wireless charging in textiles

Researchers from Drexel University, the University of Pennsylvania and Accenture Labs have developed a process for using MXene ink to print a textile energy network that can be charged wirelessly.

The next step toward fully integrated textile-based electronics making its way from the lab to the wardrobe is figuring out how to power clothing items without resorting to the unfashionable fiddling around with a solid battery. Researchers from Drexel University, the University of Pennsylvania and Accenture Labs in California have taken a new approach to solving this problem by creating a complete textile energy network that can be charged wirelessly. In their recent study, the team reported that it can power textile devices, including a heating element and environmental sensors that transmit data in real time.

Published in the magazine Materials todayThe paper describes the process and viability of constructing a mesh by printing on non-woven cotton textiles with inks consisting of MXene, a type of nanomaterial. created at Drexelwhich is at the same time highly conductive and durable enough to withstand the folding, stretching and washing that clothing is subjected to.

The proof of concept represents a major advance in wearable technology, which currently requires complex wiring and is limited by the use of rigid, bulky batteries that are not fully integrated into clothing.

“These bulky energy sources typically require rigid components, which are not ideal for two main reasons,” he said. Yuri Gogotsi, Candidate of Biological SciencesDistinguished University and Bach Professor in the Drexel College of Engineering, who led the study. “First, they are uncomfortable and intrusive to the user and tend to fail over time at the border between hard electronics and soft textiles. The problem that is particularly difficult to solve for e-textiles is the issue of washability.”

In contrast, the team’s proposed textile mesh was printed on a lightweight, flexible cotton substrate the size of a small patch. It includes a printed resonator coil, dubbed the MX coil, which can convert electromagnetic waves into energy, enabling wireless charging; and a series of three textile supercapacitors – previously developed by Drexel and Accenture Labs — which can store energy and use it to power electronic devices.

The network could charge wirelessly at 3.6V, enough to power not only wearable sensors but also digital circuitry in computers or small devices such as wristwatches and calculators. Just 15 minutes of charging produced enough energy to power small devices for over 90 minutes. And its performance showed little decline after a long series of folding and washing cycles to simulate the wear and tear of clothing.

In addition to testing the network using small electronic devices, Penn State collaborators led by Flavia Vitale, PhD, assistant professor of neuroscience, demonstrated that it could also power wireless MXene-based biosensing electrodes—called MXtrodes—that can monitor muscle movement.

“In addition to clothing applications that require energy storage, we have also demonstrated use cases that may not require energy storage,” said Alex Inman, Ph.D., who helped lead this research during his internship at Accenture Labs as a postdoctoral fellow and postdoctoral fellow. with Gogotsi in A. J. Drexel Institute for Nanomaterials. “Situations with relatively immobile users—an infant in a crib or a patient in a hospital bed—will allow for direct powered applications such as continuous wireless monitoring of movement and vital signs.”

In the same vein, they also used the system to power an off-the-shelf array of temperature and humidity sensors and a microcontroller to broadcast the collected data in real time. Wireless charging for 30 minutes provided real-time sensor feeds—a relatively power-hungry feature—for 13 minutes.

Finally, the team used an MX coil to power a fabric-printed heating element called a Joule heater, which provided a temperature increase of about 4 degrees Celsius as a proof of concept.

“Many different technologies can be powered by wireless charging. The main thing to consider when choosing an app is that it needs to make sense for a wearable device,” Gogotsi said. “We tend to think of biological sensors as a very exciting application because they are the future of healthcare. They can be integrated directly into textile products, improving data quality and accuracy, as well as improving user comfort. But our research shows that a textile-based power grid can power any number of peripheral devices: fiber-optic LEDs for fashion or occupational safety, wearable haptic devices for AR/VR applications such as learning and entertainment, and for controlling external electronics while stationary. . Using a single controller may not be desirable.”

The next step in developing this technology is to show how the system can be scaled up without compromising its performance or limiting its ability to integrate into the textile industry. Gogotsi and Inman expect MXene materials to be the key to translating various technologies into textile form. MXene ink can be applied not only to the most common textile substrates, but also to a number of MXene-based devices were also demonstrated as proof of concept.

“We produce enough energy from wireless charging to power a lot of different applications, so the next steps come down to integration,” Inman said. “ABOUTOne of the main ways MXene can help with this is that it can be used for many of these functions – such as conductive traces, antennas and sensors – and you won’t have to worry about material mismatches that could cause electrical or mechanical failure “

The research was supported by the National Institutes of Health and Accenture, LLP.

In addition to Gogotsi and Inman, Bita Soltan Mohammadlu, Katerina Shevchuk, James Fitzpatrick and Irina Roslik of Drexel; Jung Wook Park, Noah Pacic-Nelson, Eric M. Gallo and Andrea Danielescu of Accenture Labs; Raghav Garg and Flavia Vitale of the University of Pennsylvania contributed to this research.

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https://www.sciencedirect.com/science/article/pii/S1369702124002323#ab005