Smart Sensing Systems Using Wearable Optoelectronics

Abstract

A wearable smart sensing system is capable of continuously monitoring biometric information such as respiration, pulse, and body temperature while attached to an arbitrary surface on the user's body to be utilized freely during activities. Research conducted on new materials, fabrication processes, structure of electrodes, and wireless communication technologies has made constant progress in the development of smart sensing systems that use entirely wearable forms of devices to go beyond conventional devices that are based on intrinsically rigid components, such as silicon. Among various platforms that can be used in the development of smart sensing systems, optoelectronics provides innovative sensing functions (e.g., human–machine interfaces and phototherapy) that can be transferred from traditional healthcare to smart healthcare, such as point of care. Optoelectronics are light‐mediated displays that allow a light source to be controlled and a large light spectrum to be detected. Recently, this platform that uses smart and wearable optoelectronic sensing systems has become increasingly advanced to better help human beings treat their diseases through self‐healthcare. Herein, recent advanced technologies in materials, structures, and wireless platforms for smart sensors using wearable optoelectronics are reviewed.

Printable Smart Materials and Devices: Strategies and Applications

“…171 The latest researches in printed smart optoelectronic devices have demonstrated the multiscale integration of smart materials to enhance specific optical, electrical, and biological properties. 172 The further development of printed micro/ nanostructure endows the functional anisotropy and variety to optoelectronics. 172 The synergistic integration of functional properties from smart materials and the versatility of different printing technologies make it possible to achieve intelligent manufacturing of complex, heterogeneous, functional optoelectronics.…”

“…172 The further development of printed micro/ nanostructure endows the functional anisotropy and variety to optoelectronics. 172 The synergistic integration of functional properties from smart materials and the versatility of different printing technologies make it possible to achieve intelligent manufacturing of complex, heterogeneous, functional optoelectronics. Moreover, the printing strategy brings optoelectronic devices into the custom-tailored stage.…”

Printable Transparent Microelectrodes toward Mechanically and Visually Imperceptible Electronics

“…The gate electrodes were patterned on 150 nm-thick parylene dielectrics without losing the functionality of organic semiconductors because the fluorocarbon coating and VUV light exposure modify only the surface of parylene. [39] The transparent organic semiconductors were prepared by depositing a 30 nm-thick layer of 2,7-dioctyl [1] benzothieno [3,2-b][1]benzothiophene (C 8 -BTBT) via vacuum thermal evaporation. C 8 -BTBT was used because it provided stable operation under visible light illumination owing to its high optical bandgap (3.5 eV).…”

“…Flexible and transparent electronics could be extremely important for the development of wearable optoelectronic devices and systems for healthcare and biosensing. [ 1–3 ] A remarkable function of such electronics is that they can allow for multimodal assessments with electrophysiological and optical measures to monitor physiological or biological events in detail. [ 4–6 ] However, there are challenges in applying this function to versatile sensing purposes.…”

Transparent Omni‐Directional Stretchable Circuit Lines Made by a Junction‐Free Grid of Expandable Au Lines

“…[1][2][3][4][5][6][7] Transparent circuit lines that are omni-directionally stretchable and electrically invariant under large stretching are essential for stretchable optoelectronic devices. [8][9][10][11] There have been several approaches to obtain stretchable circuit lines. [12][13][14][15][16][17][18][19][20][21] Up to date, solution-processed rubber composites containing 1D conductive fillers (metal nanowires, [12][13][14][15] metal mesh, [16,17] carbon nanotubes, [18,19] metal fibers, [20,21] etc.)…”