*2.2. Hemolysis Evaluation under Fixed Shear Stress*

A rheometer (MCR 310, Physica, Anton Paar GmbH, Graz, Austria) and coaxial cylinder testing mold CC27/E were applied to provide a well-defined test environment of fixed shear stress (Figure 1). The rotor and container were immersed in 75% ethanol for 5 min for sterilization and rinsed thoroughly with normal saline (NS) at the beginning of the experiment. NS was also used to rinse the residual blood at each test interval. Pre-warmed blood (6 mL) were slowly injected into containers for each testing. The gap between a rotor and container was set as 0.5 mm and the temperature of container was maintained at 37 ◦C. The shear stress was set as 0, 25, 50, 75 and 100 Pa, with the exposure time of 5, 10 and 15 min. At the end of the tests, two 1.5 mL blood samples were collected from the bottom of the containers. Each blood sample was centrifuged twice at 3000 rpm for 5 min at a temperature of 4 ◦C. Supernatant was collected to measure the concentration of PFH and LDH, while the curves showing the changes of PFH and LDH concentrations over time at each shear stress gradient were also drawn.

**Figure 1.** Schematics of the impact of erythrocytes injury caused by mechanical shear stress force on flow patterns in bionic arteriole with stenosis segment.
