Border effects on nematic liquid crystal based thermal rectifiers

The control of heat currents in a analogous way to electrical currents is still a challenge in the development of modern nanotechnology, with possible applications such as thermal energy management, thermal logic gates and cooling of microelectronic components. A key ingredient in these systems is a device known as a thermal rectifier (thermal diode), in which heat transport occurs in a preferential direction. The impact of geometrical aspects on nonreciprocal heat transport in nanodevices is an essential aspect of the thermal management of such systems. We present results regarding the influence of border effects in the operation of thermal rectifiers based on the confinement of a nematic liquid crystal (5CB) inside two geometrical structures: a cylinder and a conical frustum. Using finite-difference methods, we determine the director field of the confined crystal and simulate the heat transport in these structures. We also employ optimization of thermal rectification via genetic algorithms. Our results provide a more realistic panorama of these devices by quantifying the influence of border effects on the optimal rectification.