A stretchable and zigzag structured hydrogel for highly sensitive strain sensors

• We proposed a zigzag structured hydrogel with high sensitivity. • The GF of the zigzag structured hydrogel can reach 2.89 at the strain of 100% • The assembled strain sensor successfully detects various human motions. • The zigzag structured strategy is widely applicable on conductive hydrogels. Hydrogel always suffers from poor sensitivity which limits their applications in the flexible devices. To address that, we designed zigzag structures onto the rectangular hydrogel which are commonly employed in recent years. The special designed structure tremendously increased the travelling distance of the mobile ions in the conductive hydrogel during the deformation of the zigzags, which lead to significant change in the resistance of hydrogel upon stretching. Therefore, the structured hydrogel achieved outstanding sensitive performance with the gauge factor (GF) of 2.89, which was almost two times higher than that of the original one. Therefore, we proposed a feasible way to adjust the sensitivity of the hydrogel, which holds great potential to be used for flexible strain sensors in healthcare, e-skin and artificial intelligence devices.