This broad function means the material can be used in a variety of applications across medicine, water and robotics. Current methods for building small tissue-like materials don't scale to sizes that can make applications possible, the researchers say. Each droplet is separated by a thin membrane, allowing the membranes to link up, similar to cell organization in human tissue. By adding certain proteins, researchers enabled the material the ability to conduct ion currents, much like nerve tissue. In another instance, researchers added a protein that allowed the tissue to tell ammonium apart from other ions in wastewaters.