John Neumann for redOrbit.com – Your Universe Online
Medical researchers foresee a time, in the not-too-distant future, when medical monitoring devices become integrated into the human body with much less interruption and discomfort for all. Doctors and patients would like the ability to monitor a patient´s vital signs without the time-consuming and costly visits to doctors´ offices.
Researchers at the McCormick School of Engineering, working with a team of scientists from the United States and abroad, have recently developed a design that allows electronics to bend and stretch to more than 200 percent their original size, four times greater than is possible with today´s technology.
The June 26 issue of the journal Nature Communications reveals a paper titled, “Three-dimensional Nanonetworks for Giant Stretchability in Dielectrics and Conductors,” and highlights some of the advances in medical device technology.
“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, Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering, who conducted the research with other research partners.
“With that level of stretchability we could see medical devices integrated into the human body.”
One primary obstacle was overcoming how stretchable electronics with solid metal parts suffered substantial drops in conductivity but this solution involves a pliable three-dimensional structure made from polymers with ℠pores´.
These ℠pores´ are filled with liquid metal which can adjust to substantial size and shape changes, all while maintaining strong conductivity. First, the team created a highly porous three-dimensional structure using a polymer material, poly(dimethylsiloxane) (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. 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.”