Layered natural oxide based soft actuators for controlling artificial motion by chemical stimulus

The chemical stimuli-based soft-actuators with complex actuation properties are of significant interest in the field of biomechanical and biomedical applications such as prosthetics. Soft actuators can manipulate and precisely control the fluid motion at the microscale and may play an important role in fluid transportation in many biological systems. Here, we have presented a two-dimensional (2D) material-based 3D printed system for the fabrication of porous soft actuators that display different actuations under the organic fluid stimulus. The few atomic layered thin chromite sheets (natural ores) show significant changes in their physical properties due to the strong interaction with organic molecules. The composite film is capable of showing controllable and sophisticated motions such as twisting, bending, rolling, and flipping in response to chemical stimuli. The introduction of porosity in the composite film dramatically increases the dynamic performances, detection range, and sensitivity. As a result, a high actuation (twisting angle) of ∼540 ± 5° and response time of ∼0.9 s was achieved, which significantly enhanced the device performance. Finally, to offer further flexibility and controlled structural alterations, we designed a snail, leaf, and worm-like soft actuators that expand the practical applications. • Two-dimensional (2D) Chromite was synthesized from natural ores. • Chromite-based 3D printed soft actuator shows high bending under acetone exposure. • Actuation behavior and working mechanisms are supported by DFT study. • The 3D printed actuator has potential to be used in controlling artificial motion.