As robotics technology transitions from rigid industrial manipulators toward compliant, flexible, and human-interactive platforms, soft robotics and artificial muscles have gained attention in robotics engineering. Soft robotic systems can navigate confined environments and perform manipulation tasks safely alongside human operators, similar to biological tentacles or trunks. However, standard soft actuators—such as pneumatic or dielectric elastomer systems fabricated from dense silicones—present performance tradeoffs. They exhibit high self-weight, slow response times, limited power densities, and susceptibility to mechanical fatigue under continuous large-strain cycling.

Three-dimensional, lightweight, and responsive aerogel composites (e.g., carbon nanotube aerogels, graphene/cellulose anisotropic aerogels, and liquid-crystal polymer aerogels) offer alternative options for soft actuation technology. Combining low bulk densities with reversible mechanical compressibility/extensibility and response times under electrical, thermal, optical, or chemical stimuli, functional aerogels act as building blocks for high-energy-density artificial muscles.

In aerogel-based artificial muscles and actuators, structural anisotropy plays a role in performance. Utilizing directional freeze-drying or magnetic-field-assisted self-assembly, scientists construct aligned, tubular aerogel architectures that mimic the hierarchical fiber organization of biological muscle tissue. When electric pulses (electro-thermal actuation) or light/thermal stimulation (photo-thermal actuation) are applied across anisotropic carbon nanotube or graphene aerogel networks, the conductive backbone generates localized Joule heating. This thermal input causes rapid expansion of gas molecules or thermo-responsive media trapped within the nanopores, driving contraction or bending deformation along predetermined axes.

These aerogel-based artificial muscles exhibit high performance metrics. Their strain rates and stress-generation capabilities exceed those of natural skeletal muscle by up to two orders of magnitude, while their bulk density remains a fraction of conventional elastomeric actuators. Consequently, soft robots incorporating aerogel artificial muscles can lift payloads thousands of times their own mass with high energy efficiency.

Furthermore, the low thermal conductivity and anisotropic heat transport of aerogels allow rapid heat dissipation during high-frequency actuation cycles, mitigating thermal degradation and material fatigue. Applications range from insect-scale soft robots that navigate tight spaces for search-and-rescue operations, to lightweight wearable exoskeletons for medical rehabilitation, and flexible end-effectors for deep-space and subsea robotic landers. Aerogels are thus providing structural and actuation mechanics for soft robotics and human-robot interaction systems.