Electromechanical actuation and control of active, living epithelia*

Biological tissues are extraordinary active materials, with each type possessing unique properties emerging from collective cell interactions and evolved to suit specific tasks. Active matter physics can help to explain these behaviors, enabling development of biophysical engineering approaches to harness them. Here, we discuss our work on engineering and controlling epithelial tissue behavior using electrical cues. Epithelia are complex cellular surfaces that provide mechanical protection (skin/cornea) and mass transport control (gut/kidney/blood-brain-barrier). Epithelial ‘superpowers’ include self-healing, conformal mapping to complex topographies, and hydraulic pumping across the tissue. Moreover, all epithelia are intrinsically electroactive, and naturally-occurring direct-current (DC) ion gradients (non-neuromuscular) help to direct both epithelial migration (healing) and fluid transport (kidney). We have previously mimicked these electric fields to allow us to accelerate epithelial self-healing, and here we will discuss a new experimental approach and theoretical modeling strategy allowing us to use these same fields to turn epithelial sheets and organoids (kidney and intestinal) into actuatable and responsive fluid pumping systems for control of 3D morphogenetic processes and scalable active hydraulic interfaces.