Financial News Agency, December 4 (Editor Huang Junzhi) The unique microstructure of the eastern bluebird (a type of North American thrush) has inspired the creation of a new type of synthetic material that is easy to produce, expandable, and strong. This material can be used in batteries and water filters.

The striking bright blue color on the wings of the eastern blue mackerel is due to a network of channels only a few hundred nanometers in diameter on its feathers. Seeing the potential of this network structure as a usable material, a team of researchers from ETH Zurich attempted to replicate it in the lab.

Using clear silicone rubber as a starting material, the researchers placed it in an oily solution and left it to swell for several days in an oven heated to 140°F (60°C). It is then cooled to reduce the solubility of the liquid and extract the rubber from the oil solution.

The researchers analyzed this material under a microscope to see how its nanostructure changed during this process. They discovered a network structure similar to a blue bird's feather. The only real difference is the depth of the grooves formed: in feathers they are approximately 200 nm, while in synthetic materials they are 800 nm.

It is reported that the key to forming a novel network structure in materials is phase separation, that is, two different phases are generated from a single uniform mixture. For example, when you try to mix oil and vinegar in the kitchen to make a salad dressing, you may find that these liquids mix when shaking, but separate when the shaking stops.

Carla Fernández-Rico, lead author of the study, said: “We are able to control and select conditions in such a way that channels form during phase separation. We have successfully halted this process before the two phases are fully merged again.”

The researchers used this method to produce synthetic materials several centimeters in size and are expandable.

“In principle, you can use rubberized plastic of any size,” Fernández-Rico said. “However, you also need a corresponding large container and oven.”

The researchers said their new material has already attracted interest from the physical community. They also said the material could be used in batteries and water filters. The latest research results have recently been published in the journal “Natural Materials”.

Specifically, for water filters, when using a channel-like structure, the ratio of surface to volume is huge, and pollutants can be removed more effectively. If the surface area is insufficient, the solid will impact the medium at high speed, causing premature degradation of the filter surface film or the underlying matrix medium. Insufficient filtration area also increases the pressure drop through the system, leading to higher energy consumption.

A battery electrolyte is a liquid or pasty solution inside a battery that transfers positively charged ions between the cathode and anode. One reason batteries lose their ability to charge or fail over time is that ions react with electrolytes, causing the electrodes to establish physical contact and damage the battery.

Solid electrolytes made of new materials can avoid physical contact between electrodes and at the same time ensure that ions pass through the battery better.

“However, the product is still a long way from going on sale,” Fernández-Rico said. “Although rubber materials are cheap and easy to obtain, the oil phase (the oil phase that does not easily dissolve in water) is quite expensive. A cheaper material is needed here.”

The researchers also plan to improve this material, with a focus on sustainability.

Fernández-Rico said, “Many natural polymers, such as cellulose or chitin, have a structure similar to the rubber we use in our work.”