‘Rubber band’ electronics can stretch to 200% their original size
US researchers have developed a method that allows electronics to bend and stretch to more than 200% their original size – four times greater than what is possible with current technology.
The team at the McCormick School of Engineering says the technology could enable medical monitoring devices which are integrated seamlessly into the human body to track a patient's vital signs and transmit them to doctors.
"With current technology, electronics are able to stretch a small amount, but many potential applications require a device to stretch like a rubber band," said Yonggang Huang, the Joseph Cummings professor of civil and environmental engineering and mechanical engineering at McCormick.
Circuits made from solid metals that are on the market today can survive a small amount of stretch, but their electrical conductivity plummets by 100 times when stretched.
Huang's team found a way to overcome this by creating a highly porous 3d structure using a polymer material, poly(dimethylsiloxane), that can stretch to three times its original size. They then placed a liquid metal (EGaIn) inside the pores, allowing electricity to flow consistently even when the material is excessively stretched.
The resulting material is said to be both highly stretchable and extremely conductive.
"By combining a liquid metal in a porous polymer, we achieved 200% stretchability in a material that does not suffer from stretch," Huang added. "Once you achieve that technology, any electronic can behave like a rubber band."
