Dissolving Silver Nanowires for Self-Destructing Electronic Implants
Vanderbilt University engineers are creating silver nanowires that dissolve in cool liquid. Using silver nanowires embedded in a polymer that dissolves in water below 32 degrees Celsius - between body and room temperature - they have made a simple circuit board that, so far, turns on an LED light. "Let's say you use this technology to make an RFID wireless tag," said Leon Bellan, assistant professor of mechanical and biomedical engineering. "You could implant important information in a person, and body temperature would keep it intact. If the tag were removed or the bearer died, it would dissolve. You could use it for implanted medical devices as well – to cause them to disintegrate, it would only require applying ice to the skin." In the lab, tiny circuit boards stay operational in water warmed by a hot plate. Turning off the hot plate causes them to start dissolving in minutes. In this system, the silver nanowires are held together in the polymer so that they touch, and as long as the polymer doesn't dissolve, the nanowires will form a path to conduct electricity similar to the traces on a circuit board. Trigger the polymer to dissolve by lowering the temperature, and the nanowire network disintegrates, destroying the conductive path.
Transcript
00:00:00 [Music] what's unique about this transient electronics platform is that the electronics will stay alive in hot water but as soon as the water cools down below a certain temperature the whole thing dissolves and disintegrates and disappears and stops working you could use it as sort of any kind of self-destructing circuit where the heat
00:00:25 required to keep the water hot might be due to a battery and so when that battery is depleted the water cools down and the whole thing disappears so let's say you would implant in something just below the skin and to remove it there's to get it to stop working instead of having to surgically remove it again you just apply ice so you locally cool that causes the material to go through this
00:00:46 transition temperature and then it dissolves in the water provided by the body this is sort of one of the side side potential application