This latest research by a Japanese academic-industrial collaboration, led by Professor Takao Someya at the University of Tokyo’s Graduate School of Engineering presents a new ultrathin, elastic display that fits snugly on the skin and can show the moving waveform of an electrocardiogram recorded by a breathable, on-skin electrode sensor. Combined with a wireless communication module, this integrated biomedical sensor system called “skin electronics” can transmit biometric data to the cloud.
|Wearable skin electronic biosensors. Credit: 2018 Takao Someya Research Group.|
The new integrated system combines a flexible, deformable display with a lightweight sensor composed of a breathable nanomesh electrode and wireless communication module. Medical data measured by the sensor, such as an electrocardiogram, can either be sent wirelessly to a smartphone for viewing or to the cloud for storage. In the latest research, the display showed a moving electrocardiogram waveform that was stored in memory.
The skin display, developed by a collaboration between researchers at the University of Tokyo’s Graduate School of Engineering and Dai Nippon Printing (DNP), a leading Japanese printing company, consists of a 16 x 24 array of micro LEDs and stretchable wiring mounted on a rubber sheet.
“Our skin display exhibits simple graphics with motion,” says Someya. “Because it is made from thin and soft materials, it can be deformed freely.” The display is stretchable by as much as 45 percent of its original length. It is far more resistant to the wear and tear of stretching than previous wearable displays. It is built on a novel structure that minimizes the stress resulting from stretching on the juncture of hard materials, such as the micro LEDs, and soft materials, like the elastic wiring a leading cause of damage for other models.
The nanomesh skin sensor can be worn on the skin continuously for a week without causing any inflammation. Although this sensor, developed in an earlier study, was capable of measuring temperature, pressure and myoelectricity (the electrical properties of muscle), it successfully recorded an electrocardiogram for the first time in the latest research.
The researchers applied tried-and-true methods used in the mass production of electronics – specifically, screen printing the silver wiring and mounting the micro LEDs on the rubber sheet with a chip mounter and solder paste commonly used in manufacturing printed circuit boards. DNP is looking to bring the integrated skin display to market within the next three years by improving the reliability of the stretchable devices through optimizing its structure, enhancing the production process for high integration, and overcoming technical challenges such as large-area coverage.
“The current aging society requires user-friendly wearable sensors for monitoring patient vitals in order to reduce the burden on patients and family members providing nursing care,” says Someya. “Our system could serve as one of the long-awaited solutions to fulfill this need, which will ultimately lead to improving the quality of life for many.”
Adapted from press release by the University of Tokyo.