Developing Desired Gallium Materials 'Like Wheat Dough'

Functional composite material based on liquid gallium synthesized by the research team

[Asia Economy Reporter Junho Hwang] Just as flour is mixed with additives to create dough with a desired taste, a new technology has been developed that can create materials with desired physical properties by mixing various particles. The physical properties can be freely adjusted depending on the types and amounts of mixed particles, promising diverse applications in electronics fields such as semiconductors.

The research team led by Rodney Ruoff, Director of the Multidimensional Carbon Materials Research Group at the Institute for Basic Science (Distinguished Professor at Ulsan National Institute of Science and Technology), announced on the 4th that they have developed a functional composite material by mixing various filler particles into liquid gallium (Ga). The research results were recently published in the international journal Science Advances.

The process of forming functional composite materials

Gallium is an element that has driven the development of human civilization in the 20th century. For example, the development of blue light-emitting diodes (LEDs) using gallium nitride became a core technology for manufacturing LED TVs. In addition, 98% of gallium consumption is concentrated in the semiconductor and electronics industries, highlighting its significant impact on modern life. However, a drawback has been its difficulty in molding. Gallium exists in a liquid state at room temperature and has high surface tension, making it difficult to obtain pure gallium.

The research team overcame this limitation by combining pure gallium with various fillers. When fillers are mixed into liquid gallium, it transforms into a viscous state similar to dough in its liquid form. Chunhui Wang, the first author and research fellow, explained, "Mixing fillers into gallium reduces the metal’s surface tension, making it easier to process. The dough-like composite material can coat device surfaces or be molded into various shapes without any special surface treatment."

They also confirmed application fields depending on the fillers. First, a functional composite made by mixing reduced graphene oxide into liquid gallium could be applied as an electromagnetic wave shielding material. When the composite material of liquid gallium and graphene oxide was coated on A4 paper, it exhibited electromagnetic wave shielding performance of up to 75 dB (decibels). This is about 3.8 times the shielding efficiency of conventional graphene oxide (20 dB). The research team evaluated that this shielding performance meets commercial standards (above 30 dB) and military standards (above 60 dB). They also confirmed that by mixing diamond particles, the composite could be used as a heat dissipation material. The research team, together with researchers from Ulsan National Institute of Science and Technology, developed a liquid gallium-diamond composite material and evaluated its thermal conductivity, recording a maximum thermal conductivity of 110 W/mK. This is more than three times higher than the thermal conductivity of pure gallium, which is about 30 W/mK. The higher the thermal conductivity, the better the heat conduction. This means it is a material advantageous for effectively solving heat generation problems in electronic devices.

Rodney S. Ruoff, Director of the IBS Center for Multidimensional Carbon Materials

Benjamin Cunning, co-corresponding author and research fellow, said, "The highest level of commercially available heat dissipation materials has a thermal conductivity of about 79 W/mK, but we were able to manufacture a material with more than 50% higher efficiency. We also demonstrated high performance in actual application experiments using the liquid gallium-diamond material as a heat dissipation material, confirming its commercialization potential."

Rodney Ruoff, director, said, "This research shows that by mixing liquid gallium with particles of various types and sizes, an alloy that remains liquid at room temperature can be produced. We hope this study will provide new inspiration for fields requiring flexible electronic devices, such as CPU heat sinks, electromagnetic wave shielding materials, and medical implants."

This content was produced with the assistance of AI translation services.