Imagine wearing a shirt that can produce electricity from your own body. It could collect energy when you move, generate more power from your sweat, store that energy, and use it to run small electronic devices.
Scientists are now working on this idea with a new technology called an e-textile microgrid. This system combines different energy-producing technologies directly into clothing. It is designed to power wearable electronics without depending on regular batteries, charging cables, sunlight, or other outside energy sources.
The technology was developed by Yin and his research team. Their system can collect energy from two natural activities of the human body: movement and sweating. These two energy sources work together to make wearable electronics more reliable and efficient.
Why Wearable Devices Need Better Power Sources
Flexible electronics are becoming more common. Today, scientists are developing smart watches, health sensors, flexible displays, fitness trackers, and other electronic devices that can be worn on the body.
However, powering these devices is still a major challenge.
Most wearable electronics use batteries. Batteries need to be charged regularly, and charging can be inconvenient. In some cases, the battery may be too large or heavy for a small wearable device.
Other wearable systems try to collect energy from the environment. For example, solar cells can collect energy from sunlight. However, they cannot produce much energy in darkness or indoors.
Some devices collect energy from body movement. But they may not work well when a person is sitting or standing still.
Sweat-powered devices also have a limitation. They need the user to sweat before they can produce energy.
The new e-textile microgrid solves these problems by combining different energy sources. When one source is weak or unavailable, another source can help.
Energy from Body Movement
The first important part of the system is called a triboelectric generator, or TEG.
A TEG can produce electricity when two different materials come into contact with each other or move against each other. This is similar to the small static electricity we sometimes feel when two materials rub together.
In the new wearable system, body movement creates this contact and friction.
For example, when a person walks or exercises, the arms move against the body. This movement can create mechanical energy, which the triboelectric generators convert into electricity.
One major advantage of this technology is that it can start producing energy almost immediately when movement begins.
This makes it useful for quickly starting a wearable device.
Energy from Sweat
The second important part of the system is a biofuel cell.
Biofuel cells can produce electricity from chemical substances. In this case, the system uses chemicals found in human sweat.
Sweat contains substances such as lactate and other natural compounds. Special materials inside the biofuel cell can use these substances to create an electrochemical reaction that produces electricity.
However, a person may not begin sweating immediately after starting an activity. This means a sweat-powered device may take some time before it can generate enough energy.
This is where the two energy sources work together.
The triboelectric generator can quickly produce electricity from movement. Later, when the person begins sweating, the biofuel cells can start producing additional energy.
Therefore, movement helps start the system, while sweat helps provide energy for longer operation.
Supercapacitors Store and Manage the Energy
The electricity produced by the movement and sweat systems is not used directly all the time.
Instead, it is managed and stored using supercapacitors.
Supercapacitors are special energy-storage devices. They can charge very quickly and release energy quickly when needed.
This is useful because different wearable devices require different amounts of power.
For example, a small digital display may need only a tiny amount of energy continuously. Another device, such as a sensor or advanced display, may need a larger amount of energy for a short period.
The supercapacitors help collect, store, and release the energy in the right way.
The researchers carefully calculated how much energy each part of the system could produce and how much energy each wearable device required. This helped them design a system that uses the available energy efficiently.
A Smart Shirt That Collects Energy
The system is designed to be placed directly on clothing.
The researchers created flexible, printed components that can be attached to textile materials. The different modules can be connected using flexible printed electrical connections.
The placement of each component is also important.
The triboelectric generators can be placed in areas where body movement creates friction, such as between the arms and the torso.
The sweat-powered biofuel cells can be placed in areas where they can remain close to the skin and collect sweat.
The researchers demonstrated a design that could be integrated into a shirt. The system was designed to remain flexible and comfortable while collecting energy from normal human activities.
The electrical connections are also protected with a water-resistant material. This helps protect the system from sweat and moisture.
The System Can Start Quickly
One of the biggest advantages of the e-textile microgrid is its ability to start wearable devices quickly.
The system can begin operating within about three minutes.
It can continuously power a low-energy device, such as a small liquid crystal display similar to the display used in a digital watch.
It can also power a sensor and an electrochromic display. This type of display can change its appearance when electricity is applied.
After only a 10-minute movement session, the system can continue powering certain devices for more than 30 minutes.
This is an important improvement because the system can continue working even after the person stops exercising.
The technology also helps reduce the time needed to start the device and can significantly increase how long the device continues to operate.
Why Combining Energy Sources Is Important
Earlier wearable energy systems often depended on only one energy source.
A solar-powered device needs light. A movement-powered device needs motion. A sweat-powered device needs perspiration.
Each technology has its own limitations.
The e-textile microgrid combines different energy sources that can support each other.
Movement can provide energy quickly. Sweat can provide energy after physical activity begins. Supercapacitors can store and manage the energy.
This makes the entire system more reliable.
The researchers describe their approach using three important ideas: compatible, complementary, and commensurate.
Compatible means that the components should be suitable for the same wearable system.
Complementary means that different components should help overcome each other's weaknesses.
Commensurate means that the performance and energy capacity of the components should be properly matched.
In simple terms, every part of the system should work well with the others.
The Future of Smart Clothing
This technology could be useful for many future applications.
Smart clothing could power health-monitoring sensors, fitness devices, digital displays, and other small electronic systems.
Future versions may use removable modules. For example, a person could replace or upgrade the energy-harvesting parts, storage units, or sensors depending on their needs.
Scientists may also develop systems that collect energy from body heat, natural body movements, and other biological processes.
In the future, similar ideas could potentially be used in medical devices placed inside the body. Such devices might collect energy from internal body movements or biological chemicals.
This could reduce the need for traditional batteries.
A Step Toward Truly Self-Powered Wearables
The most important part of this research is the idea of making different energy technologies work together.
Instead of depending on one energy source, the e-textile microgrid uses movement, sweat, and energy storage as parts of one connected system.
The result is a flexible and sustainable power system that can be built directly into clothing.
This research shows that the clothes of the future may do much more than protect us or look fashionable. They could collect energy from our daily activities and use that energy to power the electronic devices we wear.
As wearable technology continues to grow, systems like this could help create electronics that are more independent, more comfortable, and less dependent on traditional batteries and charging.
The future of wearable technology may not simply be about making smarter devices. It may also be about finding smarter ways to power them.
Reference: Yin, L., Kim, K.N., Lv, J. et al. A self-sustainable wearable multi-modular E-textile bioenergy microgrid system. Nat Commun 12, 1542 (2021). https://doi.org/10.1038/s41467-021-21701-7
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