Researchers from North Carolina State University invented a wearable device that enables you to generate electricity from your body. Love Neo in the Matrix is a new system that allows you to generate electricity with a wearable device. It has replaced the previous systems that used mass heat sinks that were massive and rigid to generate one microwatt or less. The new device is capable of generating around 20 μW/cm2. This is through the use of the body-conforming patch.
Design
They are lightweight and they conform to the shape of the body. This technology can also be embedded in a T-shirt. It contains a thermally conductive material that rests on your skin. A polymer layer rests on it followed by the TEG. An outer layer which is similar to the first layer covers the layers. The entire system is 1 cm2 and 2mm thick.
TEG was also incorporated into armbands and T-shirts which have increased electricity generation to 6 μW/cm2. When running, the device generates about 16 μW/cm2. This is due to increased movements that in turn increase the kinetic energy. Though they generate more electricity, there are not as efficient as the upper armbands which can generate around 20 µW/cm2.
It is designed in a way that it maintains a high-temperature variance across the thermoelectric material. It has also a small form factor that maintains the body temperature.
How it Works?
The conductive layer resting on your skin sits absorbs heat. The heat is prevented from dissipating to the outside air by the polymer layer. This allows the body heat to pass through wearable thermoelectric generator TEG which is centrally located. The outer layer dissipates the body heat that is not converted to electricity into the air.
It is flexible and moves through a TEG into a conductive outer layer that completely dissipates heat outside the body.
They collect heat from your body and convert it to electricity. It is used to power the wearable electronic devices. They make use of the variance between your body temperature and ambient air.
Since the device collects small amounts of electricity, it is scaled up to run low-power devices such as health monitoring wearable devices.
Optimal Location for Heat Harvesting
According to the research, some areas have a higher temperature than the others. They include the upper arm that was considered to be the best area for heat harvesting. There are other areas with high skin temperatures; however, they have some limitations such as the wrist has irregular contours which limit the surface area of contact between your skin and the wearable thermoelectric generator (TEG) band.
On the chest, the band limits air flow. As a result, heat dissipation is limited.
Pros
They generate more electricity than the previous devices with an improvement of twenty folds. It is lighter compared to the previous systems, which used the heat sinks that were heavy, stiff and bulky. It is comfortable and more efficient.
The device provides you with an easy way of powering some of your wearable devices. This is because you do not have to carry chargers or extra batteries with you. It also saves on your cash in that, you do not have to replace your batteries or chargers and also you do not require wiring.
Cons
The wearable device cannot collect enough electricity to power some devices such as a smartwatch. Thus, it is limited to powering small devices such as medical sensors.
The design leads to long-term health monitoring device.
The wearable device development nears the invention of a reliable lightweight wearable technology. It offers a reusable power source for wearable devices used for long-term health monitoring.
This system is a portion of National Science Foundation’s Nanosystems Engineering Research Middle for Advanced Self-Powered Systems of Integrated Sensors and Technologies (ASSIST). It has a room for commercialization. ASSIST aims at embedding the wearable thermoelectric generator device health tools. The tools are used to measure vital health signs. The device is to power them for long-term health monitoring.
This can lead to the elimination of bulky power cells used in medical equipment.
Conclusion
Several tens of heat watts produced by the human body are dissipated as heat flows from the skin. This depends on various conditions such as temperature and humidity. Thermodynamic laws allow heat to be converted into electricity.
Thus, the wearable device utilizes this heat to power some of your wearable devices. It is appropriate to use the necessary parameters for maximizing the device output and maintaining the body temperature.
