One recent breakthrough in display technology came when researchers were able to create flexible displays ushering in the era of folding phones. Samsung researchers have now proven that the next major change in display technology is commercially viable. The team has completed work on free-form displays with a core technology for that breakthrough being stretchable displays able to be stretched in all directions like a rubber band to change shape. Samsung researchers recently published a study outlining stable performance in a stretchable device with a highly elongated shape.
One of the most important findings in the study was that it is the first in the industry to prove the commercialization potential of stretchable devices. The new technology outlined in the study is capable of being integrated with existing semiconductor processes. Researchers combined a stretchable organic LED display and a photoplethysmography (PPG) sensor into a single device to measure and display a user’s heart rate in real-time.
Researchers called the prototype technology “stretchable electronic skin” form factor. The test case proved the feasibility of expanding the technology to further applications, and Samsung says the research will increase the uptake of stretchable devices in the future. Samsung’s OLED stretchable skin prototype can be stretched to an elongation of up to 30 percent without performance degradation.
During the study, researchers found the display continues to work stably after being stretched 1000 times. The prototype device for measuring heart rate was able to measure signals from a moving wrist accurately. The sensor picked up a heartbeat signal that was 2.4 times stronger than the signal picked up by a fixed silicon sensor.
To overcome the challenge of stretchable displays that break or degrades in performance, all of the materials and elements used, including the substrate, electrode, thin-film transistor, emission material layer, and sensor, had to have physical stretchability while maintaining electrical properties. The team replaced plastic material in the existing stretchable display with elastomer. The test system was the first to implement the display and sensor using photolithography processes, enabling micro-patterning and large-area processing.