Often used as a safe alternative to mercury in thermometers, thermostats, and switches, these gallium alloys are also good for transferring heat and electricity in soft electronics that must bend and flex. With a low melting point, they’re a liquid at room temperature. These alloys wet (stick to) both metallic and nonmetallic surfaces, and can even be used as a high-temperature lubricant for bearings. They will, however, dissolve aluminum at room temperatures and many other metals at higher temperatures. They’re also known as Galinstan.

Gallium alloys with 66.5% gallium have a lower melting temperature than those with 75.5% gallium. They are not, however, as good for transferring heat.

Gallium alloys with 75.5% gallium are better than those with 66.5% gallium for transferring heat. They also have a higher melting temperature.