Researchers in Patricia Weisensee’s lab at Washington University have developed a compact liquid metal heat switch with a passive mechanism to control the thermal management system of spacecraft. Unlike other switch mechanisms, the liquid metal version produces high conductance ratios (>150:1) while remaining compact and functions within an appropriate temperature range for space travel. The addition of a bimetallic strip in the switching channel produces a fully passive mechanism without any electromagnetic components.
Liquid metal heat switch with a conductance ratio > 150:1
Heat switches are an essential part of a spacecraft’s thermal management system, manipulating the flow of heat between a warm source and a cold sink. Vehicles experience extreme variations in temperature (-180 to 130°C daily on the moon), and the function of electronics, instrumentation, and humans onboard depends on the systems managing those fluctuations.
Stage of Research
The inventors have constructed and tested a proof-of-concept switch with a 9 cm channel that uses a gallium-indium-tin alloy. Ongoing work surrounds the optimization of the bimetallic strip that provides the passive actuation mechanism.
- Passive and compact liquid metal heat switch. NASA, 2019.
- Weisensee to develop heat transfer switch for NASA. The Source, 2019.
- Manned or unmanned spacecraft thermal management system
- Battery thermal management requiring stable temperatures
- High conductance ratios of >150:1
- Does not require active input
- Scalable at room temperature