Microphysiological system with engineered human muscle. (a) Schematic of the perfusion system showing the relation among the ferrogel pump, human tissue-engineered blood vessel (TEBV), muscle tissue and other microphysical tissue or organ systems. Q, flow rate; QM, flow rate to engineered muscle; QT, flow rate to other microphysiological tissues. (b1) Aligned three-dimensional human skeletal muscle tissue showing actin striations indicative of sarcomeres. (b2) Human endothelial cells covering a monolayer of differentiated human skeletal muscle in two-dimensional cultures. (c1) Schematic of fluidic magnetically activated ferrogel valve. (c2) Effect of magnetic field on magnetically activated ferrogel. (c3) Velocity of microparticles at 1 Hz and 5 μl/minute in fluidic channel.