Samsung has demonstrated its stretchable displays, a core technology for free-form displays, which can be stretched in all directions like rubber bands to change their shapes. Researchers at the Samsung Advanced Institute of Technology (SAIT) has unveiled this technology which is designed to “overcome the limitations of stretchable devices”. Through this study, stable performance in a stretchable device with high elongation was achieved, Samsung said.
This research also proves the commercialization potential of stretchable devices, given that the technology is capable of being integrated with existing semiconductor processes. The SAIT research team was able to integrate a stretchable organic LED (OLED) display and a photoplethysmography (PPG) sensor in a single device to measure and display the user’s heart rate in real-time, thus creating the ‘stretchable electronic skin’ form factor.
Samsung’s LED ‘skin’ display can be stretched by up to 30%
The research team was able to modify the composition and structure of ‘elastomer’, a polymer compound with excellent elasticity and resilience, and use existing semiconductor manufacturing processes to apply it to the substrates of stretchable OLED displays and optical blood flow sensors. The team confirmed that the sensor and display continued to operate normally and did not exhibit any performance degradation with elongation of up to 30 percent.
SAIT researchers attached stretchable PPG heart rate sensors and OLED display systems to the inner wrist near the radial artery. Doing this allowed them to confirm that wrist movement did not cause any property deterioration, with the solution remaining reliable with skin elongation of up to 30 percent. This test also confirmed that the sensor and OLED display continued to work stably even after being stretched 1,000 times. Additionally, according to Samsung, when measuring signals from a moving wrist, the sensor was found to pick up a heartbeat signal that was 2.4 times stronger than would be picked up by a fixed silicon sensor.
SAIT researchers replaced the plastic material used in existing stretchable displays with elastomer. The system developed by the SAIT team implements a display and sensor using photolithography processes that enable micro-patterning and large-area processing.
