Thin Metallic Heat Sink for Interfacial Thermal Management in Biointegrated Optoelectronic Devices

The applications of modern optoelectronic devices have been extended, and they now provide practical means for seamless real-time monitoring of blood flow dynamics, by being integrated with flexible and stretchable wearable sensor platform technology. However, thermal management of these devices remains limited by undesired thermal energy originating from the heating of the light-emitting diode. Specifically, the surface temperature of the optoelectronic device becomes very high compared to that of the adjacent biological tissue, causing challenges in skin-optoelectronics integration and functional deterioration of the light source. In this study, an optoelectronic module that integrates the light-emitting diode, photodetector, and a thin metallic heat sink element for sustainable in situ thermal management is developed. Experimental and computational analysis results indicate that the proposed optoelectronic device has excellent heat dissipation capabilities for thermally safe long-term usability, due to the high thermal conductivity of the device and film-type geometrical design of the embedded heat sink for skin application. The proposed optoelectronic device architecture with metallic heat sink offers an ideal option for blood flow monitoring by providing both mechanical and thermal compatibility with biological tissue suitable for long-term clinical applications.