Stretchy display acts as second skin

Display being stretched and bent

Humans could soon be wearing a second skin that doubles as a digital display after news of a new ultrathin, elastic display that can be safely worn emerged from Japan.

The material – that can show the moving waveform of an electrocardiogram recorded by a breathable, on-skin electrode sensor – is tipped for use in the home medical and care market. 

When combined with a wireless communication module, the integrated biomedical sensor system—called “skin electronics”—can transmit biometric data to the cloud.
The research was carried out by a Japanese academic-industrial collaboration, led by Professor Takao Someya at the University of Tokyo’s Graduate School of Engineering and was presented at the AAAS Annual Meeting in Austin, Texas on February 17.

The skin display, developed by a collaboration between researchers at the University of Tokyo’s Graduate School of Engineering and Dai Nippon Printing (DNP), consists of a 16 × 24 array of micro LEDs and stretchable wiring mounted on a rubber sheet.

Someya said: “Our skin display exhibits simple graphics with motion. 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 and is said to be far more resistant to the wear and tear of stretching than previous wearable displays.

It is built on a structure that minimises 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.

No pixels failed in the matrix-type display while attached snugly onto the skin and continuously subjected to the stretching and contracting motion of the body.

The nanomesh skin sensor can be worn on the skin continuously for a week without causing inflammation. The sensor, developed in an earlier study, was already capable of measuring temperature, pressure and myoelectricity (the electrical properties of muscle). Electrocardiogram recording was added as part of the latest research.

Researchers applied 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. Applying these methods will accelerate the commercialisation of the display and help keep down future production costs. 

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.

[Via The University of Tokyo]