Scientists at the College of Information Science and Electronic Engineering in China are working diligently to create tiny electronic sensors and devices that can be implanted in the body and then dissolve seemingly without a trace. They have tested several biodegradable materials, including DNA, proteins, and metals, for making transient electronics. Edging closer, their newest dissolvable device is composed of egg proteins, magnesium, and tungsten.

Transient electronics have many potential applications from localized drug delivery to pollution monitoring. Researchers have been working with an array of natural materials to test how well they perform in electronic devices and whether they might cause side effects or damage when implanted.

To develop a transient memory resistor, called a memristor, which regulates the flow of electric current and can “remember” charges, they began by spinning diluted egg albumin on a silicon wafer to turn it into an ultra-thin film. Then, they incorporated electrodes made out of magnesium and tungsten.

Testing showed that the device’s performance matched that of non-degradable memristors. Under dry conditions in the lab, the components worked reliably for more than three months. In water, the electrodes and albumin dissolved in 2 to 10 hours in the lab. The rest of the chip took about three days to break down, leaving minimal residues behind.