Doctor Kim Dae Hyung Develops a Health Surveillance Tattoo

We’re living in the era of ‘smart phones’ and thriving in the convenience that the handy gadgets bring us. Now, we receive groundbreaking news that the era of ‘smart skin’ could be just around the corner. When the technology of ‘electronic skin’ reaches its full potential, a hypothetical scenario like below could become reality.

"We sense a change in your heart rate. Also, your body temperature is too high. We suggest that you visit the hospital immediately." Out of the blue, Ms. Kim received a call from the hospital recommending she get examined immediately due to warning signs that there was something wrong with her health. She went through the examination and was diagnosed with arrhythmia (irregular pulse). Arrhythmia, if severe, can lead to cardiac arrest. It's a serious disease but most people don't realize they have it before it's too late. Fortunately, Ms. Kim was able to find out about her disease at an early stage thanks to the"electronic skin" attached to her chest. The"electronic skin" sensed her body's various signals and sent them to the hospital without delay.

Ultrathin Electronic Skin -- a Temporary Tattoo that Monitors Vital Signals

An international team of researchers in the University of Illinois developed an electronic skin that can be securely attached to the skin after smearing a little water on it. Professor Kim Dae Hyung of SNU’s Department of Chemical and Biological Engineering is one of the engineers in the research team.

Professor Kim and his team’s research was published in the famous international weekly journal, Science (2011 August 12, volume 333). When combined with the technology for storing physiological data and the technology for transmitting data across long distances, the electronic skin can be utilized to improve the wireless medical telemetry system (WMTS). This is the reason why the fruit of Kim and his team’s research is in the spotlight. This research began in August 2009 while he was studying at the University of Illinois College of Engineering. The research was completed in April this year.

The electronic skin is as thin as 37 micrometers and no thicker than a human hair. It is 2 centimeters in width and 1 centimeter in height. In the center of the skin there is a circuit that senses signals and sends data. The top and the bottom of the skin are surrounded by macro-molecule substances like a sandwich. Once the electronic skin is attached to the skin like a tattoo, it measures heart rate, muscle contractions, body temperature and brain activity. It doesn't come off easily when attached to body parts that move a lot. Also, it can remain stuck to the skin up to 24 hours.

The electronic skin is special because it is so flexible and thin that it can move with the skin. This allows the user to attach the electronic skin to bending parts of the body. One might think that the circuit in the middle would break when the electronic skin bends, but this is not so. The macro-molecule substance covering the circuit absorbs the impact from the contraction and relaxation of the skin, therefore protecting the circuit. Professor Kim says,"The more the device adheres to the skin, the more accurate the device can measure vital signs.” The Necessity of Long Distance Data Transmission Technology

The electronic skin’s circuit consists of a light emitting diode (LED) and sensors that measure heart rate, body temperature, muscle contractions and brain activity. When the device senses a specific sign, it turns on the LED to alert the user to the problem. Professor Kim says, “The device can be attached not only to the chest but also to the arm, forehead and leg. It doesn’t come off for 24 hours and keeps measuring signals throughout that time. The data can be sent wireless and can be reviewed on a real-time basis.”

Other than sensing physiological signals, the electronic skin can be used as medical equipment for the disabled. It also has gaming uses. When the device is attached to a person’s throat, it can differentiate the movement of the larynx when the person is saying simple words like “up, down, left, and right”. The device feeds the signals to a computer, which recognizes the words. This function will be helpful when making automatic wheelchairs and recreational games that can be played by just using one’s voice.

The problem is that currently the maximum distance of transmitting the physiological data is just a few centimeters. This limitation makes it impossible for the electronic skin to be applied to wireless medical telemetry technology. The electronic skin also needs a function that can store the measured data. Kim says, “I wanted to develop the electronic skin in the hopes of helping aged people or those who are suffering from brain disorders or arrhythmia. These kinds of people need continuous monitoring and I thought that the electronic skin was what could help them. I plan to continue the research in order to develop the other related technologies that are needed to utilize the electronic skin for this purpose.”

Written by JANG Hyo Jeong, SNU English Editor, fatalbonds@snu.kr
Reviewed by Eli Park Sorensen, SNU Professor of Liberal Studies
Proofread by Brett Johnson, SNU English Editor, morningcalm2@gmail.com