'Rubber band electronics' will enable seamless integration of monitoring devices with the human body to track a patient's vital signs and transmit them to doctors, making hospital visits redundant.
This would be a boon for heart patients requiring constant monitoring, permitting a battery of tests to be done at the patient's home, office or car, rather than at the hospital.
"Electronics are able to stretch a small amount, but many potential applications require a device to stretch like a rubber band. With that level of stretchability we could see medical devices integrated into the human body," said Yonggang Huang, professor of civil and environmental engineering at McCormick School of Engineering, who led the project.
Although Huang and collaborators at the University of Illinois have developed electronics with about 50 percent stretchability, it falls far short of practical applications. The key is a combination of a porous polymer and liquid metal, the journal Nature Communications reports.
First, they created a highly porous 3D structure using a polymer material (PDMS) that can stretch to three times its original size. Then they placed a liquid metal (EGaIn) inside the pores, allowing electricity to flow consistently even when the material is excessively stretched, according to a McCormick statement.
The result is a material that is both highly stretchable and extremely conductive. "By combining a liquid metal in a porous polymer, we achieved 200 percent stretchability in a material that does not suffer from stretch," Huang said. "Once you achieve that technology, any electronic can behave like a rubber band."