Premium
Flexible Blade‐Coated Multicolor Polymer Light‐Emitting Diodes for Optoelectronic Sensors
Author(s) -
Han Donggeon,
Khan Yasser,
Ting Jonathan,
King Simon M.,
YaacobiGross Nir,
Humphries Martin J.,
Newsome Christopher J.,
Arias Ana C.
Publication year - 2017
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201606206
Subject(s) - materials science , optoelectronics , photodiode , coating , photoplethysmogram , diode , light emitting diode , layer (electronics) , electronics , oled , inkwell , nanotechnology , computer science , composite material , electrical engineering , telecommunications , wireless , engineering
A method to print two materials of different functionality during the same printing step is presented. In printed electronics, devices are built layer by layer and conventionally only one type of material is deposited in one pass. Here, the challenges involving printing of two emissive materials to form polymer light‐emitting diodes (PLEDs) that emit light of different wavelengths without any significant changes in the device characteristics are described. The surface‐energy‐patterning technique is utilized to print materials in regions of interest. This technique proves beneficial in reducing the amount of ink used during blade coating and improving the reproducibility of printed films. A variety of colors (green, red, and near‐infrared) are demonstrated and characterized. This is the first known attempt to print multiple materials by blade coating. These devices are further used in conjunction with a commercially available photodiode to perform blood oxygenation measurements on the wrist, where common accessories are worn. Prior to actual application, the threshold conditions for each color are discussed, in order to acquire a stable and reproducible photoplethysmogram (PPG) signal. Finally, based on the conditions, PPG and oxygenation measurements are successfully performed on the wrist with green and red PLEDs.