A flexible liquid metal magnetohydrodynamic pump for soft robotic systems

Fluidic soft actuators enable safe, adaptable human-machine applications, but suffer from shortcomings of portability and autonomy. Herein, we introduce a liquid metal droplet based fluidic soft pump, which is lightweight (0.2 g) and compact (0.086 cm³), delivering specific pressure (18.6 - 34.88 GPa m⁻³) and specific flow rate (38.4 - 49.29 kL min⁻¹ m⁻³), surpassing existing soft and conventional pumps, and operating at low voltage ( < 1 V). Electrical energy is converted into fluid motion through the principle of magnetohydrodynamics, which harnesses the Lorentz electro-magnetic force through the liquid metal. We present the optimization of the pump design, evaluate its fundamental characteristics, and demonstrate its integration with a range of soft robotic systems. The versatility of the pump, including powering soft actuators, transferring chemical energy, and generating diverse code patterns, illustrates the potential for the development of future advanced robotic systems.