Free-floating amphiphilic picoliter droplet carriers for multiplexed liquid loading in a microfluidic channel

We present free-floating amphiphilic picoliter microcarriers for multiplexed loading in a microfluidic device. The amphiphilic microcarrier is composed of encoded hydrophobic hexagonal outer structure and hydrophilic inner structure. We fabricate these free-floating droplet carriers and assemble them in a microfluidic device for a demonstration of multiplexed liquid loading. Picoliter loading is performed by serial solution exchange of aqueous and oil phase solution. We are able to precisely adjust the loaded volume by varying the diameter and depth of the microcarrier. We also fabricate arbitrary shaped microwells and load picoliter droplets into?them. A microbead suspension is also used to demonstrate mixing via continuous oil flow. Further development of this work may be applicable to high-throughput multiplexed assays using quantized liquid loading in a microfluidic environment.