Click here to sign in with or
Devising renewable sources of energy is a key concern for scientists, political leaders and communities as the world comes to terms with the realities of climate change and the limits of the Earth's natural resources. In an exciting new development, scientists from the Institute of Scientific and Industrial Research (SANKEN) at Osaka University have demonstrated that electricity may be obtainable from water with a high salt concentration, such as seawater.
Some people think about "osmosis" as just a science term they were forced to learn in elementary school biology class. However, the spontaneous motion of dissolved ions or molecules through a semi-permeable membrane when there is a concentration difference between the two sides can be harnessed to generate electricity. And luckily for us, the oceans are filled with salty water, which may be used to help alleviate humanity's ever-growing demand for energy. However, in order to be practical, this membrane needs to be very thin and highly selective to allow ions—but not water molecules—to pass through.
Now, a research team led by Osaka University has used conventional semiconductor processing technology to precisely control the structure and arrangement of nanopores in an ultrathin silicon membrane. Because these fabrication methods have been around for decades, the costs and design complexities were minimized. Moreover, the size and location of the pores could be precisely controlled.
"Whenever there is a non-equilibrium situation, such as two water tanks with different salt concentrations, there is often an opportunity to covert this thermodynamic energy into electricity," says first author Makusu Tsutsui.
Using a single 20-nm-sized nanopore, the device reached a peak power efficiency of 400 kW/m2. However, the researchers found that adding too many nanopores to the membrane actually reduced the power that could be extracted. The optimal configuration of pores, 100-nm-sized nanopores arranged in a grid with a spacing of one micrometer, yielded an osmotic power density of 100 W/m2.
This was an important step in understanding how to design nanopore devices for best power generation. "Many other research groups are promising environmentally friendly 'green' energy, but we go one step further and propose 'blue' energy based on oceanwater that can be applied on an industrial scale," senior author Tomoji Kawai says. The study is published in Cell Reports Physical Science, and future projects may include ways to scale up the devices for real world testing. Explore further Will silicon nitride and common chemistry help revolutionize genomic sequencing? More information: Makusu Tsutsui et al, Sparse multi-nanopore osmotic power generators, Cell Reports Physical Science (2022). DOI: 10.1016/j.xcrp.2022.101065 Journal information: Cell Reports Physical Science
Provided by Osaka University Citation: Scientists demonstrate that electricity may be obtainable from water with a high salt concentration (2022, October 12) retrieved 16 October 2022 from https://phys.org/news/2022-10-scientists-electricity-high-salt.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.More from High Energy, Nuclear, Particle Physics
Use this form if you have come across a typo, inaccuracy or would like to send an edit request for the content on this page. For general inquiries, please use our contact form. For general feedback, use the public comments section below (please adhere to guidelines).
Please select the most appropriate category to facilitate processing of your request
Thank you for taking time to provide your feedback to the editors.
Your feedback is important to us. However, we do not guarantee individual replies due to the high volume of messages.
Your email address is used only to let the recipient know who sent the email. Neither your address nor the recipient's address will be used for any other purpose. The information you enter will appear in your e-mail message and is not retained by Phys.org in any form.
Get weekly and/or daily updates delivered to your inbox. You can unsubscribe at any time and we'll never share your details to third parties.
Medical research advances and health news
The latest engineering, electronics and technology advances
The most comprehensive sci-tech news coverage on the web
This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use.