The behavior of a temperature-sensitive micro-channel have been investigated in this study which mainly includes a functionally graded (FG) hydrogel as a sensor or an actuator. In order to achieve this goal, both fluid-structure interaction (FSI) and non-FSI simulations are conducted for hydrogel with homogeneous property distribution as well as FG hydrogels with different number of layers (2–16 layers). Moreover, this study investigates the FG hydrogel cross-linking density that obeys a general exponential form. In addition to all mentioned, the FG hydrogels are considered in both ascending and descending states with vertically and horizontally functionally graded property distributions (VFG and HFG hydrogels). Subsequently, the importance of the difference between the FG and homogenous hydrogels has been highlighted in the findings of the study. Besides, the FSI influence has a vital role in these structures especially once an FG material is utilized. According to the findings, the ascending and descending distributions of the hydrogel properties may significantly affect the micro-channel behavior, especially in horizontally graded type. This process can be done in a way that for descending distribution of HFG there exist no closing state for the micro-channel.
