Three-dimensional thermal analysis of wirelessly powered light-emitting systems

A theoretical model of heat conduction is developed for wirelessly powered microscale inorganic light-emitting diodes (m-ILEDs). Analytical solutions are obtained for the threedimensional temperature distribution of each component in the system, which agree reasonably well with the finite-element analyses and experiment results. A simplified scaling law is presented between the non-dimensional temperature of the m-ILEDs, and the combined geometrical parameters and thermal conductivities of the inductive receiver coil and the substrate. These results provide useful design guidelines for avoiding adverse heating of wireless m-ILEDs systems, of critical importance for bio-implanted applications.