Affiliation:
1. College of Mechanical Engineering Yangzhou University Yangzhou Jiangsu 225127 P. R. China
2. School of Electronic Science & Engineering Southeast University 2 Sipailou Road Nanjing Jiangsu 210096 P. R. China
3. Department of Electrical and Electronic Engineering and Information Systems The University of Tokyo 7‐3‐1 Hongo, Bunkyo‐ku Tokyo 113‐0033 Japan
Abstract
AbstractOwing to compact size and affordability, wearable photoplethysmogram sensors provide real‐time physiological parameters that are critical for vital signs monitoring. However, the measurement accuracy, especially during physical activities, is the main obstacle toward clinical practice. Here, ring‐shaped ultraflexible organic photodetectors （OPDs） are proposed that can form conformal contact with the skin fingerprints and monitor pulse wave under faint light source of ≈22 µW cm−2. The ring‐shape and ultraflexible design, together with optimized donor‐acceptor composition, active layer thickness, and large active area (0.1 cm2) endow the OPDs with low dark current (3.66 × 10−10 A cm−2 at −1 V), high detectivity (1.5 × 1013 Jones), and motion artifact‐free when moving at a speed of 5 cm s−1.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Natural Science Foundation of Jiangsu Province
Fundamental Research Funds for the Central Universities