A nanotool with the ability to generate electricity from salt water was made

Making a nanotool that produces electricity from salty water.

The researchers built a device that can generate electricity from salt water and water from urban taps. This work was inspired by the process of evaporation in plants.

According to Isna, evaporation is a natural process that can be seen everywhere, almost half of the sun's energy that reaches the earth is spent on evaporation processes. Since 2017, researchers have been trying to harness the energy potential of evaporation through the hydrovoltaic (HV) effect. In this device, the passage of a fluid through the charged surface of the nano device leads to the generation of electricity.

Evaporation creates a continuous flow inside the nanochannel inside this device, which acts as a pump and helps move the fluid. This effect is observed in the microtubules within the foliage of plants, where water transport occurs throughout the plant thanks to a combination of capillary pressure and natural evaporation.

Although there are currently hydrovoltaic devices, there is very little functional understanding of the conditions and physical phenomena governing energy production at the nanoscale. It's a knowledge gap that Julia Taglibo and colleagues tackled.

They performed a combination of multiple experiments and modeling to describe fluid flow, ion flow, and electrostatic effects with the aim of optimizing HV devices.

Using a new platform, this group investigated interfacial interactions in the hydrovoltaic phenomenon for the first time. The group found that the hydrovoltaic device can operate over a wide range of salinities, whereas it was previously thought that pure water was needed to achieve the best performance.

In this project, the researchers succeeded in making this device using the nanosphere colloidal lithography method. With this method, a hexagonal network of silicon nanopillars can be created with precision in a specific space. This space between the columns creates ideal channels for sample evaporation that can be easily adjusted to gain a better understanding of the effect of space limitation.

“In most fluid systems containing salt solutions, you have equal numbers of positive and negative ions,” explained one of the project's researchers. However, when you confine the liquid to a nanochannel, only ions with the opposite charge to the charged surface remain, which means current and voltage generation. As the concentration of fluid ions increases, the surface charge of the nanotool electrode also increases. As a result, we can use fluids with a higher concentration of salt, which means simplifying power generation devices that can use tap water or even salt water.”