Compartments for Synthetic Cells: Osmotically Assisted Separation of Oil from Double Emulsions in a Microfluidic Chip

Liposomes are used in synthetic biology as cell‐like compartments and their microfluidic production through double emulsions allows for efficient encapsulation of various components. However, residual oil in the membrane remains a critical bottleneck for creating pristine phospholipid bilayers. It has been discovered that osmotically driven shrinking leads to detachment of the oil drop. Separation inside a microfluidic chip has been realized to automate the procedure, which allows for controlled continuous production of monodisperse liposomes. Shrinking away turns useful: Polydimethylsiloxane‐based droplet microfluidics are used for the high‐throughput formation of double emulsions. Afterwards, the oleic acid phase can be removed through control of osmotic gradients. The method provides a technological platform for the production of monodisperse vesicles for bottom‐up synthetic biology applications.