Electrical impedance spectroscopy for skin layer assessment: A scoping review of electrode design, measurement methods, and post-processing techniques

Skin layer assessment is essential for diagnosing skin conditions or monitoring the effectiveness of treatments. To date, skin layer assessment has been extensively studied based on electrical impedance spectroscopy (EIS) as an alternative and adjuvant tools in noninvasively and portable way. The performance and functionality of EIS to assess the skin composition in each layer highly depend on the electrode design, the electrical impedance measurement method, and the postprocessing technique. To meet the market need, this review article highlights recent developments in EIS for skin assessment. Publication on the EIS developments was extracted from the three electronic academic research databases (Web of Science Core Collection (WoSCC), ScienceDirect, and PUBMED Central) to August 2023. Four hundred forty-nine papers were extracted. There are eight review papers, while one hundred thirty-five are related paper with the main topic of this study, and the rest are rejected due to not being correlated with the study. •Electrical impedance spectroscopy is a promising method for skin layer assessment.•This study relies on the difficulty of correlating the source of impedance.•The electrode design, measurement, and post-processing method are important factors.•This study provides a review of recent developments in EIS for skin layer assessment.