Rice University develops new composite materials

In nature, there are often things that look soft but extremely hard, such as deep-sea diving marine fish and mammals, whose outer skin is covered with countless tiny soft and oil-filled chambers that help the animals Withstand thousands of feet of water pressure in the ocean. Inspired by this, the research team at the Rice Research Laboratory of Rice University (RICE) recently developed a silica-gallium composite with the same properties and indicated that the mechanical properties of the material will be applied in the future.

It is reported that the researchers studied at the nano-level, they first selected polydimethylsiloxane (PDMS) as a soft encapsulation layer, and then used it to encapsulate the gallium solution to complete the fabrication of this material.

The synthesis of the material seems to be simple, but it actually took the researchers for a long time. In this regard, postdoctoral researcher Tiwary said frankly: "It is a very difficult task to use composite materials to mimic the characteristics of natural organisms compared to models that use basic materials to build an ecosystem."

Regarding the choice of gallium, Tiwary said that gallium is a liquid at room temperature. Although mercury has similar properties, unlike mercury, gallium is non-toxic and relatively easy to use. Putting it into a solid in the study often makes the solid softer, but here is the result of the combination with the selected flexible packaging layer, which gives a different effect, and the composited material becomes hard.

The choice of polydimethylsiloxane as the material for the soft encapsulant is precisely because it is inexpensive, non-toxic and inert, i.e., stable in nature. It is often used as a component in cosmetics, food additives and sealants in life. It is worth noting that when it dries, it is easy for us to see the internal liquid bubbles of the package.

At present, the material has been determined to have high energy absorption and dissipation characteristics and can be used to manufacture high energy absorbing materials or bionic structures such as artificial intervertebral discs.

But the researchers said they would not stop there. For this material, they will hand it over to the partners of the Indian Institute of Science, Roy Mahapatra and Shashishekarayya Hiremath. In the future, the Indian team will use finite element modeling and fluid dynamics to analyze the behavior of the material under mechanical stress to explore its application in life.