Particle/droplet manipulation-on-chip*

The interest in manipulating particles & droplets have found its applications in diverse fields of engineering. Generally, manipulation activities carried out in micro-devices have a fixed design for a specific task, which makes different analyses unfeasible on a single device. To address this issue, we designed a Hele-Shaw flow cell with "virtual" channels generated by sources & sinks. This device provides us the opportunity to integrate multiple functionalities onto a single-chip. 

 This work focuses on manipulating individual or several particles/droplets in the flow cell by using multiple sources & sinks to deviate streamlines. Since the depth-averaged velocity over the channel in a Hele-Shaw cell is irrotational, we use potential flow theory to predict source/sink strength for manipulating particles/droplets. This includes tasks such as deflecting particles/droplets to a different position and trapping & releasing. Hence, this single device can be used for multiple purposes such as sorting, droplet coalescence, etc., which are of interest to the oil, food and medical industries.