Dmitry Zmeev and colleagues, Lancaster University, UK, have cooled a LEGO^® figure and four LEGO^® blocks to the lowest temperature possible. The team used a dilution refrigerator (a cryogenic device that provides very low temperatures) which was made at the university. It is the most effective refrigerator in the world, capable of reaching 1.6 millidegrees above absolute zero (–273.15 °C), which is about 200,000 times colder than room temperature and 2,000 times colder than deep space.

The team found that the LEGO^® structures behave as an extremely good thermal insulator at cryogenic temperatures. This is due to the clamping arrangement between the LEGO^® blocks. This behavior is useful for construction materials used for the design of future scientific equipment like dilution refrigerators. Low thermal conductivity materials are needed for thermally isolating cryogenic components. They are especially useful for the current progression of quantum computing, which relies on isolated low temperatures for operation and coherence

The use of acrylonitrile butadiene styrene (ABS) plastic structures, such as LEGO^®, instead of the solid materials currently in use, means that future thermal insulator could be produced at a much lower cost. As a next step, the researchers want to design and 3D print a thermal insulator for the next generation of dilution refrigerators.

• LEGO^® Block Structures as a Sub-Kelvin Thermal Insulator,
  J. M. A. Chawner, A. T. Jones, M. T. Noble, G. R. Pickett, V. Tsepelin, D. E. Zmeev,
  Scientific Reports 2019.
  http://dx.doi.org/10.1038/s41598-019-55616-7