Soft actuators that respond to external stimuli like moisture, magnetism, light, and temperature have received tremendous attention owing to their promising potential in many frontier applications, including smart switches, soft robots, sensors, and artificial muscles. However, most of the conventional actuators can only be triggered by a solo stimulus and demand advanced manufacturing techniques that utilize expensive, hazardous, and synthetic raw materials. Herein, we design and fabricate a multiple stimuli-responsive actuator using graphene oxide, Fe3O4 nanoparticles, and tapioca starch via a water evaporation-induced self-assembly method. The resultant hybrid actuator exhibits a bending speed of ∼72° s–1 upon moisture exposure. Moreover, it can perform clockwise and counterclockwise rotations, linear motion, and magnetic object capture by regulating a magnetic field. As representative examples, the actuator is used to fabricate various smart devices such as smart curtains, biomimetic structures, and a smart gripper that undergo complex and consecutive motion under the influence of multiple stimuli.

No abstract

Actuators triggered by water evaporation have found potential applications in a wide range of emerging fields, including smart structures, power generators, artificial muscles, and soft robots. In addition to poor mechanical performance, conventional actuators raise major economic and environmental concerns due to their expensive and complex synthesis processes with hazardous chemicals and high ecological footprint. Herein, a nacre‐inspired moisture‐responsive actuator is fabricated using graphene oxide (GO) and tapioca starch (TS), a water‐soluble, low‐cost, and eco‐friendly natural polymer. The resultant TS/GO nanocomposite film has excellent mechanical properties and exhibits rapid and autonomous locomotion under moisture attack. Moreover, the actuator demonstrates a bending speed of ≈60° s−1 and has the potential to lift a load up to ten times its own weight. Based on these features, a novel moisture detection alarm system with control and operating circuits is assembled using the TS/GO film. Furthermore, the TS/GO actuator shows that it is capable of mimicking biological structures like flowers and can undergo locomotion even for nonwater vapors like isopropyl alcohol, ethanol, and chloroform.

No abstract

No abstract