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Galinstan Alloy
Galinstan: The Liquid Metal Alloy
Mercury-free, room-temperature fluid for medical, electronics, and more.
Galinstan is a eutectic alloy of gallium, indium, and tin that remains liquid at room temperature. As a non-toxic alternative to mercury, it has found applications in various fields requiring low-melting-point metal.
Properties & Quick Facts
| Property | Value | Notes |
|---|---|---|
| Composition | Ga (~68.5 wt%), In (~21.5 wt%), Sn (~10 wt%) | Eutectic mixture of three metals |
| Melting Point | ~ −19 °C | Stays liquid well below room temperature |
| Density | ~6.44 g/cm³ | Slightly higher than water (~6.44×) |
| Viscosity | ~2.4 mPa·s | Similar to water (~1.0 mPa·s) |
| Surface Tension | ~0.534 N/m | Higher than water, lower than mercury |
| Boiling Point | ~1300 °C (est.) | Decomposes at high temperature |
| Wetting Properties | Non-wetting on glass | Unless oxide forms on the surface |
| Key Uses | Thermometers, cooling systems, lab experiments | Mercury replacement in many applications |
Conceptual 3D Model
Conceptual 3D representation of Galinstan's metallic mixture (not an actual crystal structure).
Applications
Galinstan has become an important material in various fields, particularly where a non-toxic liquid metal is required. Here are some key applications:
Thermometers & Medical Devices
Galinstan replaces mercury in medical thermometers and other diagnostic tools, eliminating toxic hazards.
Cooling Systems
Used in high-performance computing and electronics for liquid cooling systems due to excellent thermal conductivity.
Heat Transfer & Research
Facilitates laboratory experiments requiring liquid metal at ambient temperatures without toxicity concerns.
Mercury-Free Switches
Creates environmentally friendly electrical switches and connectors that leverage its conductive properties.
Element Breakdown
Galinstan combines the unique properties of three distinct metals to create its remarkable characteristics:
Symbol: Ga
Atomic Number: 31
Key Role in Galinstan: Lowers melting point significantly, major constituent
Fun Fact: Pure gallium can melt in your hand (m.p. ~29.8 °C)
Symbol: In
Atomic Number: 49
Key Role: Modifies physical properties like viscosity and surface tension
Industrial Use: Widely used in transparent electrodes (ITO)
Symbol: Sn
Atomic Number: 50
Key Role: Helps stabilize the alloy and fine-tune the melting point
Historical Fact: Tin has been used since the Bronze Age to create bronze (copper-tin alloy)
Temperature vs. Viscosity
Approximate viscosity trend with increasing temperature (indicative data).
Safety & Handling
Best Practices
- Avoid unnecessary contact with aluminum surfaces (can cause corrosion).
- Store in sealed, inert containers to prevent oxidation.
- Clean-up: easily handled with standard lab procedures.
Environmental Impact
Eco-Friendly Alternative
Galinstan is a more environmentally friendly alternative to mercury, with:
- No toxic vapor hazard at room temperature
- Safer handling and disposal requirements
- Lower environmental impact in case of spills
Gallium is largely sourced as a byproduct of bauxite/aluminum refining, though increasing demand may impact availability and pricing.