Gallium-indium eutectic

The eutectic Gallium–Indium alloy is a liquid metal with a melting point of 15.7 °C and a range of useful properties, including good electrical and thermal conductivity, mechanical flexibility, moldability, and low toxicity. It is commonly used as a safer alternative to mercury in applications such as thermometers. The alloy readily forms a thin oxide layer on its surface, which allows it to be cast into intricate shapes and makes it particularly well suited for flexible and soft electronic devices. It is also widely used as an electrode material in molecular electronics.

For example, researchers at the University of Groningen in the Netherlands employed Gallium–Indium eutectic electrodes that could be injected into microfluidic channels due to the alloy’s mechanical properties. These channels remained stable while avoiding damage to soft organic dielectric materials, enabling reliable measurement of their dielectric properties.

References:

1. Ge, W., Wang, R., Zhu, X., Zhang, H., Sun, L., Wang, F., Li, H., Li, Z., Du, X., Chen, H., Zhang, F., Shi, H., Hu, H., Xi, Y., He, J., Hu, L., & Lan, H. (2024). Recent progress in eutectic gallium indium (EGaIn): surface modification and applications. Journal of Materials Chemistry A, 12(2), 657–689. https://doi.org/10.1039/D3TA04798A
2. Zhao, Z., Soni, S., Lee, T., Nijhuis, C. A., & Xiang, D. (2023). Smart Eutectic Gallium–Indium: From Properties to Applications. Advanced Materials, 35(1), 2203391. https://doi.org/10.1002/ADMA.202203391
3. Douvogianni, E., Qiu, X., Qiu, L., Jahani, F., Kooistra, F. B., Hummelen, J. C., & Chiechi, R. C. (2018). Soft Nondamaging Contacts Formed from Eutectic Ga–In for the Accurate Determination of Dielectric Constants of Organic Materials. Chemistry of Materials, 30(16), 5527–5533. https://doi.org/10.1021/ACS.CHEMMATER.8B02212