Researchers Develop Shape-Shifting Fluid Battery for Flexible Electronics
TEHRAN (Tasnim) – Scientists at Linköping University have created a groundbreaking soft battery made with fluid electrodes, capable of taking any shape—a potential game-changer for future wearable and embedded technologies.
Their findings, published in the journal Science Advances, introduce a soft, flexible power source that could revolutionize how electronic devices are designed and integrated.
"The texture is a bit like toothpaste. The material can, for instance, be used in a 3D printer to shape the battery as you please. This opens up for a new type of technology," said Aiman Rahmanudin, assistant professor at Linköping University.
The innovation comes amid projections that over a trillion devices will be connected to the Internet within a decade.
Beyond conventional electronics like smartphones and smartwatches, this includes wearable medical equipment such as insulin pumps, pacemakers, hearing aids, and health-monitoring sensors.
In the longer term, applications may expand to include soft robotics, electronic textiles, and implanted neural devices.
To support this growth, battery technology must evolve.
“Batteries are the largest component of all electronics. Today they are solid and quite bulky. But with a soft and conformable battery, there are no design limitations. It can be integrated into electronics in a completely different way and adapted to the user,” Rahmanudin said.
Working with the Laboratory of Organic Electronics (LOE), Rahmanudin and his colleagues created a stretchable, form-fitting battery by transforming solid electrodes into a fluid state.
Previous efforts to develop stretchable batteries relied on mechanical features—such as rubbery composites or sliding contacts—but did not resolve the underlying issue of rigidity caused by thicker electrodes.
“Here, we've solved that problem, and we're the first to show that capacity is independent of rigidity,” said Rahmanudin.
Earlier attempts at fluid electrodes, often using liquid metals like gallium, met with limited success.
Such materials typically functioned only as anodes and risked solidifying during charge cycles.
Additionally, many earlier flexible batteries relied on rare materials with significant environmental costs.
In contrast, the Linköping researchers based their battery on conductive plastics—specifically, conjugated polymers—and lignin, a byproduct of paper production.
The result is a rechargeable battery that maintains performance over 500 cycles and can stretch to double its original length without functional loss.
“Since the materials in the battery are conjugated polymers and lignin, the raw materials are abundant. By repurposing a byproduct like lignin into a high-value commodity such as a battery material, we contribute to a more circular model. So, it's a sustainable alternative,” said Mohsen Mohammadi, postdoctoral fellow at LOE and one of the study’s lead authors.
The next challenge is to raise the battery’s voltage.
“The battery isn't perfect. We have shown that the concept works but the performance needs to be improved. The voltage is currently 0.9 volts. So now we'll look at using other chemical compounds to increase the voltage. One option that we are exploring is the use of zinc or manganese, two metals that are common in Earth's crust,” said Rahmanudin.
