LEGO® Block Structures as a Sub-Kelvin Thermal Insulator

Abstract

We report measurements of the thermal conductance of a structure made from commercial Acrylonitrile Butadiene Styrene (ABS) modules, known as LEGO® blocks, in the temperature range from 70 mK to 1.8 K. A power law for the sample’s thermal conductivity κ = (8.7 ± 0.3) × 10−5 T 1.75±0.02 WK−1 m−1 was determined. We conclude that this ABS/void compound material provides better thermal isolation than well-known bulk insulator materials in the explored temperature range, whilst maintaining solid support. LEGO blocks represent a cheap and superlative alternative to materials such as Macor or Vespel. In our setup, <400 nW of power can heat an experimental area of 5 cm2 to over 1 K, without any significant change to the base temperature of the dilution refrigerator. This work suggests that custom-built modular materials with even better thermal performance could be readily and cheaply produced by 3D printing.

Magnetic Cooling and Vibration Isolation of a Sub-kHz Mechanical Resonator

“…This is achieved by gluing the wire to LEGO® blocks attached to each mass of the mass-spring system. The extremely low thermal conductivity of LEGO® blocks in the mK range [34] guarantees the thermal isolation of the silver wire from the mixing chamber without the need to compromise the vibration isolation.…”

Shared special interest play in a specific extra-curricular group setting: A Minecraft Club for children with special educational needs

“…Topics cover a wide range of subjects, from renewable energy, to plant propagation, to ultra-low-temperature Lego (Chawner et al, 2019), and children are encouraged to suggest topics they would like to be covered. This flexible approach avoids highlighting differences in ability between children, allows them to explore their own interests within the topics, and draws a clear distinction between the club and formal education settings.…”