These electronics dissolve when triggered

A medical device, once its job is done, could harmlessly melt away inside a person’s body. Or, a military device could collect and send its data and then dissolve away, leaving no trace of an intelligence mission. Or, an environmental sensor could collect climate information, then wash away in the rain.

Dissolvable electronics do their job, then disappear

Researchers have developed tiny electronic devices that can be used in medical implants and which melt right away when they're finished with.