A Multi-Parametric Finite Element Analysis of Heat Distributions in Implanted Micro-LEDs

Optogenetics is a breakthrough neurostimulation technology which enables precise optical control over the function of neurons that have been genetically engineered to feature light-sensitive opsin proteins. With notable exceptions, the light source is typically placed externally, and light is guided in via optical fibres. This is advantageous because the light source is less constrained in terms of size, power and heat generation. This comes at the disadvantage of needing a permanent hole in the blood brain barrier so efforts to fully implant the light source, with wireless communication and power are needed. Here we present a multi-parametric finite element analysis of the heat distribution generated by typical micro-light emitting diodes in optical implants, encapsulated by a polymer. Our simulation results have elucidated the relationships between the temperature rise at the device/tissue interface and irradiance, encapsulation thickness and time.