Image: University of Cambridge
The researchers, from the University of Cambridge, took their inspiration from electric eels, which stun their prey with modified muscle cells called electrocytes.
Like electrocytes, the jelly-like materials developed by the Cambridge researchers have a layered structure, like sticky Lego, that makes them capable of delivering an electric current.
The self-healing jelly batteries can stretch to over ten times their original length without affecting their conductivity – the first time that such stretchability and conductivity has been combined in a single material.
The jelly batteries are made from hydrogels: 3D networks of polymers that contain over 60% water. The polymers are held together by reversible on/off interactions that control the jelly’s mechanical properties.
The ability to precisely control mechanical properties and mimic the characteristics of human tissue makes hydrogels ideal candidates for soft robotics and bioelectronics; however, they need to be both conductive and stretchy for such applications.
“It’s difficult to design a material that is both highly stretchable and highly conductive, since those two properties are normally at odds with one another,” said first author Stephen O’Neill, from Cambridge’s Department of Chemistry. “Typically, conductivity decreases when a material is stretched.”
In addition to their softness, the hydrogels are also surprisingly tough. They can withstand being squashed without permanently losing their original shape, and can self-heal when damaged.
The researchers are planning future experiments to test the hydrogels in living organisms to assess their suitability for a range of medical applications.
Source: University of Cambridge
Image: University of Cambridge