Wearable Sweat Sensors: Background and Current Trends

Abstract

Sweat‐related physiology research has been well established over the years. However, it has only been around ten years that sweat‐based sensing devices started to be explored. With the recent advancements in wearable activity and physiology monitoring devices, sweat was investigated for its contents similar to blood and corresponding wearable devices were studied intensively. This article provides a thorough review on sweating mechanisms, sweat sensing devices, and electronic technologies for sweat sensor implementations. Potential future directions and recommendations based on current research trends were provided in each section. This review aims to offer a unique perspective from both physiology and engineering point‐of‐view to draw a complete landscape of the sweat sensing research.

A wearable fluidic collection patch and ion chromatography method for sweat electrolyte monitoring during exercise

“…To give an overview of current sweat sensor developments, several literature reviews are published. [23][24][25][26][27] Secondly, researchers use microfluidics systems for sweat sensing purposes. Ma et al designed a patch that contains a wick and a microfluidic channel that collects the sweat and brings the sweat to the electrode of the sensor.…”

A Flexible 3D Organic Preamplifier for a Lactate Sensor

“…[7][8][9] Various methods have been studied to determine the lactate concentration of human sweat. [10][11][12][13] Electrochemical sensing is the most common method used for this purpose because it is selective, cost-effective, and allows for rapid detection. [14] The most common strategies utilize enzymatic amperometric sensors, in which enzyme-functionalized electrodes catalyze a reduction-oxidation (redox) reaction to initiate electron transfer, which is transduced as an electrical current.…”

Microfluidics by Additive Manufacturing for Wearable Biosensors: A Review

“…Here, the microfluidics typically provides continuous sampling by conveying the sweat along a controlled fluidic channel and then enhancing the sensing in a well-defined encapsulated acquisition chamber. Thin microfluidic layers are typically designed as sweat collectors to bring the sweat on the electrodes, preventing any further re-absorption of the electrodes back to the skin, and also preventing sweat evaporation [ 59 , 60 ]. If built with soft and flexible materials, microfluidics easily addresses some of the requirements for wearable devices, such as being lightweight, comfortable, and conformable [ 58 ].…”