Generating and Using Electricity from the Bloodstream
Chinese researchers are working on a generator to produce electricity from the bloodstream. The less than 1-millimeter thick Nanogenerator works the same way as hydropower generator. As the blood flows, its force rotates the tiny turbines that produce electricity. The lightweight generator promises a safer and inexpensive solution to power medical devices. Currently, these devices rely on batteries which have to be replaced regularly using costly surgeries.
Providing reliable power to wearable devices, implants, and other smaller devices is thus a challenge. Charging or connecting them to power using wires is either difficult or impractical. As such, developers have been looking for alternative sources of energy. One option for the medical devices is to generate electricity from the bloodstream. Others include harvesting the energy from the body heat or movements.
Challenges of powering implants devices in the human body
The modern-day devices go beyond the confines of a building’s electrical wiring. Some rely on alternative energy sources such as solar and wind. The flexible nature of solar makes it favorable for a wide range of applications. But, it does not work with some smaller devices such as the medical implants.
Most of the medical devices only needs tiny amounts of electricity to operate. Such devices include the blood pressure sensors, pacemakers, neurostimulators, drug-delivery pumps and more. Due to their small physical size, they have limited battery capacities. Yet, any loss of power to the device exposes the patients to life-threatening risks.
The batteries or the implants must be replaced after a number few years. And this requires expensive and difficult surgeries. Additionally, there are risks of infections during the surgeries or from leaking batteries.
For easy replacements, the doctors must install the devices in easy-to-access locations. However, this may reduce the efficiency of the device and complicate the installation procedure.
Generating electricity from the bloodstream eliminates the need for the batteries and frequent surgeries. It also allows placing the device closer to the area of application.
Producing electricity from the bloodstream
The Fudan University scientists are using a similar concept to that of hydropower generation. But, the production of electricity from the bloodstream is on a smaller scale.
The force of the blood flow drives the turbines of the Fluid-Fiber Nanogenerator (FFNG). This generator uses ultra-thin fibers from carbon nanotubes which makes its trubine very light and easy to turn. Despite the small size, the electro-active nanotubes are flexible, strong and stable.
The team is yet to try the generator on a human being but was successful during a lab test using a frog. They need to first determine if this power is enough to supply the medical devices. In addition, they must address the legal and safety issues. This means that it will take some time before using the technology inside the human body.
Advantages of producing electricity from ambient sources
This nanogenerator has the potential to power the internal medical devices or charge wearable technology. But, the system for the external application is complex since it will also need plugs and appropriate circuitry.
Harvesting electricity from the bloodstream has benefits such as:
- This ambient energy is not weather dependent and has the ability to provide continuous and reliable power.
- Reducing the number of surgeries and risks of infections.
- Allows placing the device close to the area of application for improved efficiency.
Why the FFNG is better than Nano-scale motors
The FFNG is superior to a previous approach of using Nano-scale motors floating in the blood. The operation of the Nano-scale motors could lead to blood clots and put the patients at risk. This technology was thus abandoned on safety grounds.
The FFNG nanogenerator is stable, safer, and more efficient. So far, it is generating 20% using a saline solution.
There are other methods for generating electricity from the human body. Some are in still development stages, while others produce insufficient power, or are unsafe. A typical technology in progress is using the piezoelectric devices to harvest energy from the body heat.
Harvesting electricity from the bloodstream is a promising technology with many benefits. Once developed, it will reduce the reliance on batteries and frequency of expensive surgeries for the medical implants.
The bloodflow is almost constant throughout and does not dependent on the weather. As such, nanogenerators will provide continuous and reliable power to the devices. Finally, the stable electricity from the bloodstream will improve the efficiency and reliability of the device.