  Inspired by the unique design of the shells of snails inhabiting the deep-sea
hydrothermal environment, here we theoretically study the temperature response
of a bilayer to an external thermal impulse. A semi-analytical solution to the
temperature field in the bilayer is obtained, allowing us to assess the peak
temperature that occurs on the inner wall as a quantitative indicator of the
thermal resistance of the bilayer. The structural determining factors of the
thermal resistance of a bilayer are then investigated by examining the effects
of the stacking sequence and volume fractions of the constitutive layers on the
peak temperature on the inner wall. Our results indicate that the stacking
sequence of the two layers in a bilayer, as well as their volume fractions,
play important roles in determining the thermal resistance. For two layers with
given materials, there exists an optimal stacking sequence and thickness ratio
giving rise to the best thermal resistance. The results of our work not only
account for the unique laminated design of the snail shells from hydrothermal
environments but also provide practical guidelines for the design of multilayer
thermal barriers in engineering.
