Bacteria can be made undetectable to the immune system with the use of encapsulation. Hydrogels are suitable for this purpose. Hydrogels are water-absorbing (synthetic) polymers, and are therefore able to form a layer around the bacteria. Due the low reactivity of this hydrogel capsule towards the immune system and permeability to small essential molecules (for example nutrients and wastes). With the use of microfluidic techniques, the amount of bacterial cells per liquid droplet is relatively easy to control. In the produced microfluidic droplet, hydrogel formation can be induced. The result is a hydrogelation from the outside towards the core of the droplet, surrounding the entire group of bacteria. The problems with these current techniques are: inhomogeneous hydrogelation (due to gelation form the outside to the core), uncontrollable cell growth inside the encapsulation, thus incontrollable drug release, and non-degradable encapsulations. The conventional encapsulation technique is visualised in Figure 1.