Optical detection heterogeneously integrated with a coplanar digital microfluidic lab-on-a-chip platform

The intimate integration of optical components with microfluidics technology will enable next generation portable LoC systems that may completely contain optical generation, processing, and detection. Toward the chip scale integration of digital microfluidics with active compound semiconductor devices, heterogeneous integration technology is used in this paper to integrate thin film (approx 1 micron thick) compound semiconductor photodetectors with digital microfluidic systems. Each thin film InGaAs photodetector is bonded onto a glass platform, coated with Teflon AF, and integrated into the digital microfluidics system. The detection function is tested using the mixing and digital droplet movement of chemiluminescent compounds, which clearly indicate the functionality of the microfluidics system and the integrated thin film InGaAs photodetector.