Wearable and Biocompatible Blood Oxygen Sensor Based on Heterogeneously Integrated Lasers on a Laser-Induced Graphene Electrode

Abstract

Wearable electronics or epidermal electronics have attracted growing interest for their expansion into markets as health monitors and for biological applications. However, a key obstacle lies in the light source and the optical path change caused by the deformation and displacement in the measurement. In this work, we demonstrated a wearable and biocompatible blood oxygen monitor by using heterogeneously integrated vertical cavity surface emitting lasers (VCSELs) and a Si photodetector (PD) on a Au-laser-inducedgraphene hybrid electrode. The strategy for fabricating a flexible electrode provides advantages including large-scale fabrication, high cost performance, and simple operation. The full widths at halfmaximum of the 680 and 808 nm VCSEL were 1.8 and 0.8 nm, respectively, which is useful to improve sensitivity. Then, the rigid optoelectronics including narrowband VCSELs and a thinned Si PD were heterogeneously integrated on the flexible electrodes. Owing to the great flexibility and excellent light source, the wearable device conformal to the skin's surface can be utilized to extract blood oxygen (SpO 2 ). It was successfully demonstrated that the flexible device can extract the photoplethysmography signals of various regions including the fingernail, the wrist, and the earlobe. This work proposes an alternative strategy to miniaturizing an integrated device for long-life and continuous medical monitoring.

Blood pressure measurement techniques, standards, technologies, and the latest futuristic wearable cuff-less know-how

“…Similar kinds of photonic devices based on organic and inorganic and visible to infrared photodetectors are also reported to measure arterial pulse wave. 151–157…”

“…Similar kinds of photonic devices based on organic and inorganic and visible to infrared photodetectors are also reported to measure arterial pulse wave. [151][152][153][154][155][156][157] Han et al presented a flexible polymer sensor for dynamic physiological signals. 147 The sensor was fabricated using P(VDF-TrFE-CFE) copolymer and PET substrate via a spincoating technique (Fig.…”

Recent Progress on Graphene Flexible Photodetectors

“…For example, single-layer or few-layer graphene atoms are thin and exhibit high flexibility. Graphene-based devices can be bent and cycled many times without affecting their performance by placing them on flexible substrates [ 12 , 155 ]. Recently, it was found that the special 3D structure of graphene heterojunction PDs promotes device functions that cannot be realized by planar geometric structures.…”

Facile Fabrication and Analysis of Highly Sensitive PtTFPP/Carbon Black/Polystyrene Oxygen-Sensitive Composite Films for Optical Dissolved-Oxygen Sensor

“…Oxygen is a crucial element for the proper functioning of the human body. − It plays a key role in several reactions in the fields of medicine and chemistry. , Oxygen exists in diverse forms in nature, including the form of dissolved oxygen, , which is the oxygen exchanged between a solution and the atmosphere or that dissolved in water through chemical reactions. , It holds significant importance as an indicator in aquaculture. − Maintaining an appropriate oxygen level is very important to aquatic life; both excessively high and low levels can be very dangerous. For instance, fish may suffocate and die if the dissolved-oxygen level falls below 4 mg/L .…”