fig5
Figure 5. Flexible optoelectronics for soft electronics. (A) Photographs of an OLED photonic skin under skin-attached (left) and wrinkled state (right). Reproduced with permission from ref[52]. Copyright 2020, John Wiley and Sons; (B) Optical images of a wearable photoplethysmograph sensor with QD-LED/PD (left) and real-time PPG signal graph measured by QD-stretchable LED and -conventional LED (right). Reproduced with permission from ref[53]. Copyright 2017, American Chemical Society; (C) Photographs of a flexible PPG sensor based on PLED and OPD. Reproduced with permission from ref[54]. Copyright 2016, AAAS; (D) Photograph of a wireless WμLED, showing various alphabets; (E) Forward voltage/irradiance changes of the WμLED during 100,000 bending operations (r = 2.5 mm) (left), and I-V curves of the WμLED with various device sizes (right). Reproduced with permission from ref[56]. Copyright 2019, Elsevier; (F) Photograph of an RGB micro-LED display, attached onto a glass rod (r = 3 mm); (G) Current-voltage curve of the
