text: The mechanical properties of the fibers are tested, but the process can be tricky due to practical reasons. The mechanical properties are tested with Universal Test Machine by fixing the hydrogel fibers between two holders. However, due to the compress of the holder, hydrogel fiber might have a trend to break at the holding point. Also, the loss of water during the test will impact the resulting data, and precaution needs to be taken to meditate the loss. And the tensile strength of the hydrogel fiber is usually smaller than 1 MPa.