Study on Molecular Thermal Energy Transfer in a Lipid Bilayer

Recently, lipid bilayers attract a great deal of interest as a material with nanoscale structure. Various devices utilizing lipid bilayers, which include some kinds of sensors and molecular sorting devices, have been proposed. Understanding of thermal energy transfer in the lipid bilayers is important for utilizing the lipid bilayers as a new material for NEMS with nano structures. In this study, we have investigated the energy transfer along and across the bilayer membrane by molecular dynamics simulations of the lipid bilayer in liquid water. We found that along the bilayer membrane, thermal energy flux in the lipid bilayer is much smaller than that in the water layer. On the other hand, in case of thermal energy transfer across the membrane, total thermal resistance of the lipid bilayer-water system is composed of thermal resistances of various parts of the system, including water layer, head group of lipid, and tail hydrocarbon chain of lipid, which exhibit different magnitude of values. It is found that the tail hydrocarbon chains of lipid have the highest thermal resistance.