Fig. 1

Synthesis and properties of 4D-CTH. a The thermoreversible sol–gel transition of the CTH between 4 and 37 °C. Scale bar = 5 cm. b The preparation process of 4D-CTH. c The structure of CTH prepared via 4D printing (left). 4D-CTH became gelatinous at 37 °C (right). Scale bar = 1 cm. d Electron micrograph of 4D-CTH. Scale bar = 200 μm