Room-temperature liquid-metal particles are a burgeoning material platform for stimuli-responsive electronics, self-healing circuitry, stretchable/flexible conductors, drug delivery, and wearable devices. The ability to chemically tune the nanoscale surface oxide of liquid-metal particles is critical to these applications. To this end, a method of silanizing liquid gallium alloy particles has been developed. The benefits of alkoxysilane ligands are demonstrated by orthogonal functionalizations to produce chemically diverse, multifunctional hybrid liquid-metal nanoparticles. Additionally, architected stretchable conductors, called polymerized liquid-metal networks, were fabricated using hitherto inaccessible chemistries with enhanced electromechanical performance. These advancements have downstream implications for particle processing, device fabrication, long-term stability, and functional behaviors of liquid-metal particle systems.

Advances in materials, designs, and controls are propelling the field of soft robotics at an incredible rate; however, current methods for prototyping soft robots remain cumbersome and struggle to incorporate desirable geometric complexity. Herein, a vat photopolymerizable self-healing elastomer system capable of extreme elongations up to 1000% is presented. The material is formed from a combination of thiol/acrylate mixed chain/step-growth polymerizations and uses a combination of physical processes and dynamic-bond exchange via thioethers to achieve full self-healing capacity over multiple damage/healing cycles. These elastomers can be three dimensional (3D) printed with modular designs capable of healing together to form highly complex and large functional soft robots. Additionally, these materials show reprogrammable resting shapes and compatibility with self-healing liquid metal electronics. Using these capabilities, subcomponents with multiple internal channel systems were printed, healed together, and combined with functional liquid metals to form a high-wattage pneumatic switch and a humanoid-scale soft robotic gripper. The combination of 3D printing and self-healing elastomeric materials allows for facile production of support-free parts with extreme complexity, resulting in a paradigm shift for the construction of modular soft robotics.