Rechargeable emission of multicolor ML fluids in an artificial circulatory system. (a) Schematic showing the setup of the artificial circulatory system. (b-e) True-color images of the tubing filled with ML fluids composed of (b), ZnS:Cu,Al (c), ZnS:Mn (d), and CaTiO3:Pr (e) when FUS was on (top) and off (bottom). All scale bars represent 1 mm. (f-g) Representative dynamics of light emission intensity from ML fluids composed of (f), ZnS:Cu,Al (g), ZnS:Mn (h), and CaTiO3:Pr (i) in the artificial circulatory system. The gray ticks on the top represent FUS pulses.