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A galactomannan hydrogel has the characteristics of renewability and biodegradability. It has good prospects in flexible sensors and soft robot technology. However, it is still a challenge to prepare galactomannan hydrogel sensors with soft/hard controllable conversion and conductivity properties. In this paper, galactomannan, borax, and NaCl were introduced into a poly-N-isopropylacrylamide network to obtain a hydrogel with a double network structure. This hydrogel has a higher compressive strength (3.80 MPa), higher elongation (1370%), and higher conductivity (4.40 S/m). In addition, the hydrogel exhibits soft/hard controllable conversion and shape memory properties. It can be used as a flexible underwater gripper. The resistance curve shows that the prepared hydrogel can be used as a sensor to monitor and distinguish all kinds of small movements and sound changes of the human body through the change of the resistance signal. This hydrogel shows great potential in the fields of sustainable wearable sensors, artificial skin, flexible sensors, and soft robots.

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The manufacture and functionalization of transparent wood (TW) have recently attracted extensive interest. However, it is still a challenge to prepare flexible TW with high conductivity and optical switch. In this study, octadecyl methacrylic acid (ODMA) is used as optical switch. Sodium chloride and silver nanowires (AgNWs) were used to improve the conductivity. N, N‐bis (acrylamide) cysteamine (BACA) was used as a binder between AgNWs and wood. Acrylamide is used to impregnate delignified wood substrates and can polymerize with BACA. Then, poly (acrylamide co octadecyl methacrylate) (PAMODMA) wood with tunable transmittance, flexibility and high conductivity(resistance 1.2 Ω, conductivity 6364.8 s/m)was prepared after curing. The transmittance and phase transition temperature of PAMODMA wood can be adjusted by ODMA. After 350 cycles of bending, the resistance of wood has no significant change. PAMODMA wood has a broad application prospect in intelligent window, sensor, intelligent robot and other fields.