Stretchable substrate concept and prototype (via McCormick University)
The words ‘stretching’ and ‘electronics’ are not terms we usually associate with one another. However, researchers from McCormick University have literally bridged that grammatical rift with their development of ‘rubber-band electronics.’ Elastic or stretchable electronics have been around for some time, usually embedded into silicon or polyurethane substrates, but their elasticity only goes so far (about 50% of their size) before conductivity of electricity is lost.
While their stretch ability makes them an ideal choice for some of today’s applications, like flexible solar-cells, they are not really efficient for medical monitoring of the human body. In order to incorporate electronic monitoring devices inside of human beings, such as heart patients where monitoring is crucial, the electronics need to be able to flex and conform beyond the 50%, or so. This is where the research team comes in. Their rubber-band like flexible electronic platform is able to stretch to an astounding 200% of original size, making future stretchable medical devices integrated into the human body a decidedly real possibility.
To accomplish their goal, the researchers created a substrate made of polydimethylsiloxane (fancy term for a silicon-based organic polymer) which is able to stretch to over 3 times its original size. In order for the team to maintain electrical conductivity for electronics, the pours (or gaps) were filled with EGaln (eutectic gallium indium), a liquid metal, which is able to provide a consistent current over the substrate even when stretched like a rubber-band. Their findings may be able to be adapted for use in ultrathin flexible video screens that you could fold up and carry in your pocket, or incorporated into mobile devices that could fit in your wallet. Then again, the possibilities of what the stretchable material could be used for are pretty flexible.
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