On–Chip Droplets Sensing using Capacitive Technique

Significant attention has been given on the development of droplets–based microfluidic system because of its potential and apparent advantages. Beside the advantages of reducing the sample volume, it’s also offer less time consuming for the analysis. Optical and fluorescence among the famous method that was used in detection of droplets but they are normally bulky, expensive and not easily accessed. This paper proposed a simple, low cost and high sensitivity for droplets sensing in microfluidic devices by using capacitive sensor. Coplanar electrodes are used to form a capacitance through the microfluidic channel. The design of eight pair of electrodes was used to detect the presence of a droplet. Changes in capacitance due to the presence of a droplet in the sensing area is detected and used to trigger the microscope to capture the image of detected droplets in microchannel. The measurement of droplets detected and counting are displayed through a LABVIEW interface in the real time.