Chemically Engineered Devices for Skin Analysis: A Comprehensive Mini-Review

Abstract

Among all organs in humans, the skin is considered the largest organ and is covered on the surface of the human body. It is continuously exposed to and affected by many harsh conditions, like natural, chemical, and anthropogenic nanomaterials, from external and internal contributions. This phenomenon may cause irreversible health effects, from skin corrosion to cancer. Thus, there is an increasing demand for minimal monitoring of everything that may jeopardize skin conditions, especially human facials. These include noninvasive in situ analysis of body fluids that may contribute to unhealthy skin in the human body. This adaptation urges the researchers to develop many types of electrochemically active materials and wearable biosensors. This attempt with mechanically soft and flexible materials enables them to suit the geometric nonlinearity of the human skin. For each device's design, its purpose is different. Therefore, this mini-review will summarize the developments of skin analyzers with chemical engineering design. In short, this review will cover five type of skin conditions with different analyzers: (i) normal skin conditions; (ii) sweat skin analysis; (iii) skin hydration; (iv) skin wounds; and (v) the secretion of organic chemicals through the skin. For each criterion, the reaction of each analyte to the sensor performance was also discussed. Special attention is also included regarding the safety, usage, and reusability of the devices. In certain cases, there is also data security, which the authors may consider elaborate. From here, the authors hope that this review can benefit those interested in developing future commercialized sensors for skin analysis.