Droplet Morphology Correction in Single-planar EWOD Devices to Enhance Luminescence Detection Sensitivity

Gravity-induced sagging leads to increased distortion in the droplet profile near the solid-liquid free surface and the progressive failure of simple geometric approximations especially for large contact angle or droplet volume conditions. This morphology distortion could induce unintended optical noise and focus shift to the optical detection (e.g. luminescence detection) where droplets behave as micro-lenses. Here, we demonstrate a simple approach to calculate the Young-Laplace equation for the morphology of sessile droplets on EWOD surfaces with variable volumes. The results could be utilized in the future as an effective guide for calibrating the position of photodiodes and improving the sensitivity in optical detection process.