Actuation concepts for in vivo-like mechanical strain
Various actuation concepts can be used to generate membrane stretching. Mimicking stretching forces in vitro for cell culture is often required, for example in lung-on-chip tissue culture (breathing), in heart-on-chip models (heartbeat) or gut-on-chip (peristaltic intestine movement). We will briefly outline the most common and promising principles, including pneumatic actuation, electromagnetic actuation, piezoelectric actuation and dielectrophoretic actuation used in microfluidic organ-on-chip technology. 1. Introduction Cells and tissues in the human body are naturally exposed to different types of mechanical forces. The forces range over multiple length scales. For instance, our bones and cartilage are exposed to compressive loads as we walk and move and our blood vessels are continuously exposed to shear stresses due to vascular flow and to cyclic strain due to blood pressure or lung tissue is under mechanical…