Setting the time factor for the electronics was a bit more complex. "The key word is control -- to make it disappear in a controlled way," Huang said. An electronic material that can dissolve in the body itself has very little control over how long it lasts. However, by putting an encapsulation layer made of magnesium oxide around the device, researchers could control the dissolution time "very precisely... between a few hours or as long as six months."
To create a device that can last a longer period of time, researchers design it with a thicker encapsulation layer. For a shorter dissolution period, the device will have either no layer or a very thin one. "We can control the magnesium oxide thickness," Huang said. However, even this is a delicate science, as "electronics have their own performance goals, which means you can't make this layer too thick" to impede on those, he added.
So far, researchers have tested one application of the transient electronic device, creating a device with a microheater that can be inserted into a wound to kill bacteria and aid with healing.
Aside from medical applications and the potential for consumer devices, these types of transient electronics can also benefit other scientific endeavors. "It can be used for environmental health monitoring, such as in an oil spill," allowing researchers to put a device inside seawater that can record conditions and then dissolve, leaving behind no impact on the environment, Huang said.
Huang, Omenetto, and their colleagues expect to continue their work for the next few years. Once there is approval from the Federal Drug Administration for use of the devices in medical applications, practitioners will have the go-ahead to use them on patients. However, this type of approval is likely many years down the line, according to Huang.