A Comprehensive Review of the Recent Developments in Wearable Sweat-Sensing Devices

Abstract

Sweat analysis offers non-invasive real-time on-body measurement for wearable sensors. However, there are still gaps in current developed sweat-sensing devices (SSDs) regarding the concerns of mixing fresh and old sweat and real-time measurement, which are the requirements to ensure accurate the measurement of wearable devices. This review paper discusses these limitations by aiding model designs, features, performance, and the device operation for exploring the SSDs used in different sweat collection tools, focusing on continuous and non-continuous flow sweat analysis. In addition, the paper also comprehensively presents various sweat biomarkers that have been explored by earlier works in order to broaden the use of non-invasive sweat samples in healthcare and related applications. This work also discusses the target analyte’s response mechanism for different sweat compositions, categories of sweat collection devices, and recent advances in SSDs regarding optimal design, functionality, and performance.

Colorimetric sweat analysis using wearable hydrogel patch sensors for detection of chloride and glucose

“…It is a laborious and time-consuming process that prohibits the development of sweat analysis. 48 Recently, wearable sensors have emerged as an auspicious option to realize synchronized sweat collection and sweat measurement, dramatically streamlining the whole sweat analysis process. 49 Meanwhile, our investigated colorimetric assays allow the hydrogel patches to thoroughly the color variation that correlated with concentrations of target analyte within 1 min, thus making it possible to be applied for the wearable real-time sweat analysis.…”

Liquid Metal–Polymer Conductor-Based Conformal Cyborg Devices

“…Sweat only contains a limited number of biomarkers, and some intermediate products produced during metabolic processes are not excreted through sweat or are present in such low quantities that they cannot be detected. In addition, there is a certain degree of hysteresis associated with sweat detection. , For hormones and other biomarkers that undergo rapid metabolism, their levels in the human body can fluctuate greatly with changes in mood and other physiological alterations over time. Thus, to achieve accurate and reliable monitoring of physiological indicators, it is important to use multiple detection methods and to integrate data from different sources.…”

Epidermal Wearable Biosensors for Monitoring Biomarkers of Chronic Disease in Sweat

“…This sensor integrates physiological indicator detection technology with wearables, which can obtain basic physiological indicators at various states [ 155 , 175 , 176 , 177 , 178 ]. With the development of sensor technology and people’s increasing attention to their own health conditions, more and more physiological monitoring equipment is being developed [ 179 , 180 , 181 ]. Wearable technology can be used to establish a wearable physiological monitoring system to realize the continuous and long-term monitoring of physiological information in patients.…”