The advantages of durable, long-lasting electronics are well established and, indeed, desirable in electronic devices large and small. But in what scenario would you want a device to dissolve away leaving no trace? The truth is, from military to medicine, "transient electronics" has a great many potential applications. The latest research team to shift its focus to this emerging field is a group from Iowa State University, which is developing materials that can melt away when remotely triggered.
Previous research in the area has explored the use of transient materials to create dissolvable devices, such as transistors, resistors and diodes. The goal of Iowa State's research was to investigate how the rate of transiency could actually be controlled.
The team experimented with a blend of programmable biodegradable and transient insulating polymer films. It found that by adding gelatin to the mix, dissolution was slowed, while the addition of sucrose worked to speed up the rate of transiency. Using these special polymers, the team was able to build and test an antenna that was capable of sending data and then completely dissolving when a trigger was activated.
One constant in this experimentation with different composite structures is that the material maintains the appropriate physical properties to function as a substrate for electronics. As such, the researchers are now conducting further studies, centered on developing degradable polymer-based materials that would make suitable platforms for other electronic components, including work on transient LED transistor technology.
Though this area is at present largely unexplored, the team emphasized the potential applications of transient electronics in the commercial world.
A lost credit card could vanish from existence (but most likely still leave your debt behind), a secret diary could be programmed to self-destruct should it be removed from its hiding spot, and sensors stored with food could indicate when it has reached temperatures that would cause the food to spoil.
The real-world application for transient electronics with perhaps the most potential is in the field of military strategy, as similar research efforts from DARPA would indicate. Should a soldier carrying sensitive information be captured, injured or worse, their electronics could be triggered to melt away before any classified information was gleaned by enemy forces.
In demonstrating its progress, the team has produced a video that shows a blue light-emitting diode mounted on a polymer base with electrical leads embedded. When it comes into contact with just a drop of water, the base and leads begin to dissolve and the light goes out. This process can be seen in the video below.
The team presented its research at a recent meeting of the American Chemical Society in Dallas. Some of the work was also outlined in recent paper published in the journal Advanced Functional Materials.
Source: Iowa State University