Dongwuk Jung

1 Introduction Biological signals provide crucial clues for understanding the states and mechanisms of biological systems including humans.[1] Among many types of sensing approaches, optoelectronic sensors usually composed with paired light sources and photodetectors have become widely used for real-time monitoring of biological signals in ways of photoplethysmography (PPG),[2, 3] near-infrared spectroscopy (NIRS),[4, 5] and pulse oximeter.[6-9] The optoelectronic sensors are advantageous as...

Abstract Stretchable electronics are of huge interest as they can be useful in various irregular non-planar or deformable surfaces including human bodies. High density multi-functional stretchable electronics are beneficial as they can be reliably used in more compact regions. However, simply stacking multiple layers may increase induced strain, reducing degree of stretchability.