Researchers at the National University of Singapore have developed a soft robot that uses magnetic fields for both motion and power management. The system integrates flexible zinc–manganese dioxide batteries with magnetic actuation, allowing the robot to move, sense its surroundings and manage its energy supply without external power connections. The study was published in Science Advances.
The research team, led by Assistant Professor Wu Changsheng from the College of Design and Engineering, designed a robot inspired by the form of a manta ray. Its power system consists of vertically stacked flexible batteries embedded in a silicone body. According to the researchers, magnetic fields generated by the robot’s actuators stabilised the electrochemical processes inside the batteries during operation. Laboratory tests showed that the batteries retained 57.3% of their capacity after 200 cycles under magnetic enhancement, compared with lower retention in samples without magnetic exposure.
The team reported that magnetic fields influenced zinc ion movement within the battery and reduced dendrite formation, which can cause short circuits. They also found that the fields affected manganese oxide structures in the cathode, limiting degradation during repeated cycling.
To demonstrate the concept, the researchers built a prototype that uses magnetic fields for fin movement and steering. The soft robot incorporates onboard sensing and wireless communication. During testing, it carried out manoeuvres such as straight-line swimming and turning, while transmitting data for digital reconstruction. The onboard sensors enabled it to detect obstacles and adjust its path. Additional sensors monitored environmental conditions, including temperature variations in water.
The group plans to expand the sensing functions of future versions and investigate whether magnetic enhancement can be applied to other battery types or forms. The project involved collaborators from Tsinghua University, the University of California, Los Angeles, and Dartmouth College.
