Soft robots—machines made from flexible, squishy materials—are designed to move gently and adapt to tight or delicate spaces.
They can glide through water, squeeze into pipes, or handle fragile objects without causing damage.
But even though these robots are soft and adaptable, their power sources are not.
Traditional batteries are rigid, heavy, and wear out quickly when bent or stretched. This has limited the independence of soft robots, often forcing them to stay connected to an external power supply or accept a shorter working life.
A research team led by Assistant Professor Wu Changsheng at the National University of Singapore has found an innovative way to turn this weakness into a strength.
Their study, published in Science Advances, shows that the same magnetic fields used to control soft robots can also make their flexible batteries stronger and more reliable.
By using one physical principle—magnetism—to drive both movement and power, the team created a robot that is more efficient, more durable, and closer to true “embodied intelligence,” where sensing, movement, and energy management work together as one system.
The team developed flexible zinc–manganese dioxide batteries encased in soft silicone. Instead of arranging the batteries side by side, they stacked them vertically, which saved space and kept the robot body flexible.
Their design was inspired by manta rays, whose natural shape integrates movement, sensing, and energy use in a smooth and efficient way. The researchers wanted their robot to mimic this biological elegance.
During experiments, the researchers found that the robot’s magnetic actuators—the parts that move its fins—also produced magnetic fields strong enough to improve the chemistry inside the batteries. These fields slowed down the growth of dendrites, which are sharp metal structures that can form inside batteries and cause dangerous short circuits. Because the magnetic fields controlled ion movement inside the battery, they helped zinc spread evenly during charging, keeping the battery safe and stable even when the robot bent repeatedly. After 200 charge cycles, the enhanced batteries kept 57.3% of their capacity, nearly double the performance of batteries without magnetic assistance.
Further study revealed why this worked. The magnetic field created a Lorentz force, which redirected ion movement in the electrolyte, leading to smoother and more uniform zinc deposition. At the same time, the magnetic field aligned the electron spins within the manganese oxide material, strengthening the internal structure and preventing crystal breakdown during repeated use. This dual stabilizing effect allowed the batteries to remain flexible, safe, and long-lasting—ideal for soft robots operating in unpredictable environments.
To show the technology in action, the team built a soft robot shaped like a manta ray. It carried flexible batteries, soft magnetic actuators, and a lightweight circuit that allowed sensing and wireless communication. By applying external magnetic fields, the researchers could make the robot flap its fins, steer through water, and stabilize its movement across different surfaces. The same magnetic fields powering the movement also kept the battery functioning smoothly, demonstrating a powerful integration of motion and energy.
The robot also displayed simple decision-making abilities. Sensors detected obstacles, and the robot automatically adjusted its path to avoid collisions. When pushed off course by waves or bumps, its control system corrected its orientation within moments. Temperature sensors allowed it to map heat patterns in the water, showing potential applications in environmental monitoring.
Looking forward, the team plans to add more advanced sensors to the robot, such as ultrasonic devices for object detection or chemical sensors for water-quality analysis. They are also exploring whether magnetic enhancement could boost other types of batteries, including lithium-ion cells or wearable battery fibers.
Assistant Professor Wu hopes this work will lead to soft robots capable of exploring pipelines, caring for marine ecosystems, or supporting surgeons—all without sacrificing flexibility or battery life.
By combining movement and power in a nature-inspired design, the researchers are bringing soft robotics one step closer to behaving like living organisms.
Source: National University of Singapore.
