South Korea has developed a smart tattoo that will be used as a health monitoring device

If a scientific team's project succeeds, South Koreans may soon be able to carry a device inside their bodies in the form of a custom tattoo that warns them to potential health concerns. Researchers at Korea Advanced Institute of Science and Technology (KAIST) in Daejeon, south of Seoul, have created an electronic tattoo ink made out of liquid metal and carbon nanotubes that acts as a bioelectrode.

It can send a readout of a patient's heart rate and other vital signs such as glucose and lactate to a monitor connected to an electrocardiogram (ECG) device or another biosensor. The researchers ultimately want to be able to dispense with biosensors.

"We want to be able to connect a wireless chip integrated with this ink, so that we can communicate with each other or send signal back and forth between our body and an external device," said project leader Steve Park, a materials science and engineering professor.

In principle, these devices may be placed virtually anywhere, such as in the homes of patients. The ink is non-invasive and is composed of tiny particles based on gallium, a soft, silvery metal that's also utilized in semiconductors and thermometers. Decorative platinum coating on carbon nanotubes helps to conduct electricity while also contributing to durability.

"When liquid metal is applied to the skin, it does not come off with rubbing, which is impossible with just liquid metal," Park added.