Local researchers said they developed an electronic patch that can check health by monitoring sweat.
On Thursday, the Korea Advanced Institute of Science and Technology (KAIST) announced that Professor Kwon Kyeong-ha of the Electrical Engineering Department and Professor Kim Jong-uk of the Chemical Engineering Department of Sungkyunkwan University have developed a wireless electronic patch that the volume flow and the total amount measures sweat loss in real time
To easily collect sweat as a biomarker, one must use the discoloration that occurs when reacting with chemical reagents. To do this, one has to measure the sweat flow rate and the accumulated loss in real time.
A wireless electronic patch (left) measures the volume flow and accumulation loss of sweat. The microfluid system (right) measures chloride, pH, creatine and glucose at the same time. (Image credit: KAIST)
The research team developed a wearable, wireless, electronic patch that can be used to monitor sweat flow rate and loss. Using the discoloration, the platform was integrated into microfluidic systems to analyze the welding components.
In order to monitor the sweat release rate in real time, the researchers developed a “module for recording the thermal flow”. They created an elaborate microfluidic channel to allow the collected sweat to flow through a narrow passage and placed a heat source on the outer surface of the channel to induce heat exchange between the sweat flowing in the channel and the heated channel.
As a result, the researchers could develop a wireless electronic patch that could measure the temperature difference at a given location before and after the heat source with an electronic circuit and convert it to a digital signal to measure the sweat release rate in real time.
The patch accurately measured sweat rates in the range of 0 to 5 microliters / minute (μl / min), which was considered physiologically significant, the KAIST said.
The research team successfully measured chloride, glucose, creatine concentration, pH and volume flow in sweat. The research team said these indicators could be used to diagnose cystic fibrosis, diabetes, kidney dysfunction, and metabolic alkalosis.
With the sweat flowing in the microfluidic channel completely separated from the electronic circuitry, the new patch overcame the shortcomings that made existing flowmeters prone to corrosion and aging.
The patch can be easily attached to the skin using flexible circuit board printing technology and silicone sealing technology and has a sensor that detects changes in skin temperature.
With a smartphone app, a user can review data measured with the wearable patch in real time.
“The wireless electronic patch can be widely used for personal hydration strategies, identifying symptoms of dehydration, and other health management purposes,” said Kwon.
The patch can also be used in a systematic drug delivery system, such as measuring the rate of blood flow in blood vessels near the surface of the skin or measuring the rate of drug release in real time to calculate the exact dosage, he added.
The KAIST said it applied for the technology patent from John Rogers, a professor at Northwestern University, and Wearifi, a wearables developer in Boston, United States
The study was published in Natures Electronics in March, entitled “An On-Skin Platform for Wireless Real-Time Monitoring of Flow Rate, Cumulative Loss and Weld Temperature”.
