A team of engineers and materials scientists from the U.S. has developed a groundbreaking design that enables battery pouches to become far more flexible and stretchable than ever before. Their innovative approach, described in a recent paper published in Matter, shows that by strategically placing holes of a specific size and shape in particular locations, it’s possible to turn a battery pouch—traditionally only slightly flexible—into one capable of stretching significantly or even folding 180 degrees without compromising performance.
This discovery is part of a broader effort to integrate electronics more seamlessly into everyday life, particularly through wearable technology. Over the last couple of decades, as electronics have shrunk in size and improved in durability, textile manufacturers have been trying to incorporate these advancements into clothing. The goal has been to create smart garments that can display digital messages, change colors or patterns, and serve other interactive functions. However, a significant challenge in making such clothes functional has always been powering them.
Many wearable devices, like simple health trackers, consume such minimal power that they can be powered by the wearer’s movements. But for more advanced devices—like those that display content, change colors, or run complex applications—powering them reliably is still a challenge. While traditional batteries work well in many devices, their size, weight, and rigidity make them difficult to incorporate into clothing. Furthermore, the safety risks associated with batteries, such as the potential for overheating or fires, have remained a significant concern.
In this context, the team’s work is a major breakthrough. The new design focuses on creating a battery that is not only flexible and bendable but also incorporates a cooling mechanism to prevent overheating, which is a major issue in wearable technology. The resulting battery is not only more adaptable to the shape and movement of clothing, but it is also safer and more efficient than previous designs.
The Design of the New Battery
Traditionally, pouch batteries—the type commonly used in various electronic devices—are somewhat flexible but are typically limited in how far they can bend or stretch. To explore the potential for greater flexibility, previous researchers have experimented with creating holes in the battery material, using round or square cuts in different configurations. These attempts were aimed at increasing the flexibility of the batteries, but the results were often unsatisfactory or came at the cost of the battery’s capacity.
The new research takes this concept a step further. Instead of random holes, the team strategically cut rectangular holes in the battery material. These holes come in both longer and shorter shapes, which helps maintain the structural integrity of the battery while allowing for more stretchability. The placement and dimensions of these holes were carefully selected after testing how they impacted the flexibility and stretching properties of the battery.
Through extensive experimentation, the researchers discovered that this particular arrangement of holes significantly enhanced the stretchability of the battery. The battery design was capable of withstanding stretches of up to 10% of its original length. Furthermore, the battery maintained its ability to hold a charge even when folded 180 degrees, a feat that was previously difficult to achieve without damaging the device.
Benefits of the Design
This flexible battery design offers several compelling advantages that are crucial for integrating electronics into clothing. One of the most impressive results of the research was that the battery could undergo 100 folds/unfolds without experiencing any loss in performance. This durability is vital for wearable electronics, which are subject to frequent movement and bending.
Additionally, the researchers found that the battery design was not only more breathable than traditional batteries but also twice as breathable as cotton. This is a critical factor for wearables, particularly in clothing, as it ensures that the device remains comfortable to wear, even for extended periods. The breathable design helps improve airflow and reduce the buildup of heat.
Speaking of heat, another major innovation in the new battery design is its heat dissipation capabilities. The strategically placed holes in the battery help dissipate heat more efficiently, preventing overheating, which is a significant concern in battery-powered wearables. The cooling effect of the holes allows the battery to operate safely and efficiently, even in challenging conditions.
Potential Applications in Wearable Electronics
With this new battery design, the possibilities for wearable electronics are significantly expanded. Clothing integrated with flexible, lightweight batteries could support a range of smart applications. For instance, smart shirts with embedded flexible displays could change colors or show real-time data, such as health metrics or environmental information. Smart jackets could include heating or cooling elements powered by these batteries, or even interactive displays for communication and entertainment.
The new flexible battery could also be a game-changer for other applications beyond clothing. Wearable medical devices, like heart rate monitors, temperature sensors, and biosensors, could be integrated directly into the skin or clothing, offering more comfort and flexibility than ever before. As these types of devices require both reliability and flexibility, the new battery design makes them much more practical for everyday use.
Moreover, the ability to fold and stretch the battery without compromising its performance also opens up opportunities for other flexible electronics that could be used in sports gear, headgear, and even furniture. For instance, smart helmets with integrated sensors, or smart shoes that can monitor a wearer’s activity and health data, could now incorporate these flexible batteries without being restricted by size or shape.
Conclusion
The work of this engineering and materials science team marks a significant step forward in the quest for flexible and safe wearable batteries. By strategically incorporating holes in the battery material, they have created a design that is stretchable, foldable, and breathable—all while maintaining battery capacity and preventing overheating. These advancements not only make wearable technology more comfortable and practical but also open up exciting new possibilities for its future applications.
This development is an important piece of the puzzle in the broader effort to make wearable electronics a part of everyday life. As the design is refined and further tested, it may become an essential component in the next generation of smart clothing and wearable devices. By addressing key challenges such as size, weight, stiffness, and safety, these researchers have made a critical contribution to the future of wearable technology.
Reference: Lin Xu et al, Stretchable, breathable, wearable batteries using a holey design, Matter (2025). DOI: 10.1016/j.matt.2025.101959