Multi-Stimuli Responsive Soft Actuator with Locally Controllable and Programmable Complex Shape Deformations

Abstract

The soft actuators capable of responding to multiple stimuli and adapting to changing environments have attracted growing interest in the flexible multifunctional materials. However, how to achieve high degree of freedom (DoF), precise control, and complex shape transformation of the multi-stimuli responsive soft actuator, still remains challenging. Here, we report a multi-responsive soft actuator with various controllable sophisticated deformations by integrating a magnetically sensitive elastomer (MSE) with a liquid crystal elastomer (LCE). Through regulating the stimuli strength and the geometrical dimensions and material parameters of elastomers, the bending angle and curling curvature of the actuator are accurately controlled ranging from 0 to 58.9° and from 0.23 to 1.29 cm–1, respectively. The facile material-structural synergistic design drives the complex 3D shape deformations (e.g., bidirectional bending, shrinkage/bending, rolling/bending, and twisting/bending) of the actuator. More importantly, due to its photosensitive characteristics, the shape-morphing of the actuator can be manipulated locally and sequentially, which markedly enriches the DoFs. The flower-shaped actuator displays multiple deformation modes, and the hand-shaped actuator transforms between 8 gestures under the control of laser and magnetic field, proving that the multi-responsive soft actuators have great application potentials in future bioengineering, soft manipulators, and flexible electronics.

Vapor and Light Responsive Biocompatible Soft Actuator

“…In nature, living organisms like venus flytraps, scales of pine cones, and sundew plants exhibit shape deformations in response to various physical and chemical perturbations in surrounding environmental conditions. − Inspired by these natural phenomena, researchers have developed artificial shape-deforming devices known as soft actuators in laboratories. These devices are made up of soft and compliant materials and are capable of undergoing shape deformation under various input stimuli like light, − heat, electric , and magnetic fields, solvent vapor. ,, Soft actuators find applications in various fields such as soft robotics grippers, wearable textiles, , smart switches, and biomedical devices. , Among these stimuli, light and water offer advantages due to their abundance and accessibility. Light-responsive soft actuators can be remotely controlled via UV–visible or infrared light, utilizing either photochemical or photothermal mechanisms.…”

“…1−3 Inspired by these natural phenomena, researchers have developed artificial shape-deforming devices known as soft actuators in laboratories. These devices are made up of soft and compliant materials and are capable of undergoing shape deformation under various input stimuli like light, 4−6 heat, 7 electric 8,9 and magnetic fields, 5 solvent vapor. 6,10,11 Soft actuators find applications in various fields such as soft robotics grippers, 12 wearable textiles, 10,13 smart switches, 11 and biomedical devices.…”

Magnetoactive Soft Materials with Programmable Magnetic Domains for Multifunctional Actuators

“…Despite recent advancements in the area of soft actuators, two significant challenges remain in their design and manufacture: optimizing drive systems and simplifying manufacturing processes . To achieve shape programming and customization, stimulus-responsive soft actuators that rely on functional polymers must be finely designed to achieve synchronous configuration of the chemical structure, flexibility, and programmed shapes. − Various approaches such as anisotropic expansion, liquid crystal transformation, and phase transition can be employed to create double-layer flexible deformation systems. − This typically involves high-cost manufacturing techniques, complex internal architectures, and multistep assembly processes. Time-dependent mechanisms such as diffusion and molecular organization may result in slow response times and compromised driving efficiency. , Another type of actuator that uses pneumatic and hydraulic systems involving elastic materials requires complex tethering structures and fluid delivery networks .…”