Researchers Demonstrate a Rubber-Like Solid-Polymer Flexible, Foldable, and Stretchable Battery
Based on a solid, rather than gel-like, polymer electrolyte, the battery proved stretchable to nearly twice its original length.
A team of researchers from Stanford University, Shanghai Jiao Tong University, Nanjing University, and Nanyang Technological University have created an experimental battery which can be safely bent, twisted — and even stretched, a key feature for future wearables.
“Until now we haven’t had a power source that could stretch and bend the way our bodies do," explains co-author Zhenan Bao, of what makes his team's creation special, "so that we can design electronics that people can comfortably wear."
The new, soft battery is based on polymer electrolytes — similar to those found in modern lithium-polymer (LiPo) batteries. Where the new material differs, though, is that the polymer is a soft and stretchable solid rather than the usual liquid goo — always at risk of leaking if the battery is subjected to mechanical stresses.
In lab testing, a prototype solid-polymer battery — roughly the size of your thumbnail and storing around half as much energy as a traditional polymer battery of the same weight — was able to maintain a constant power output while being squeezed, folded, and even stretched to almost twice its original length.
The team's work on the prototype has been published under open access terms in the journal Nature Communications; Stanford student David Mackanic, meanwhile, has confirmed that the team is working to increase the energy density to compete with traditional battery types as well as building larger versions — including versions which may power body-worn health sensors currently in development under Stanford's BodyNet project.