Numerical modelling of the interaction between eccrine sweat and textile fabric for the development of smart clothing

Abstract

PurposeLive non-invasive monitoring of biomarkers is of great importance for the medical community. Moreover, some studies suggest that there is a substantial business gap in the development of mass-production commercial sweat-analysing wearables with great revenue potential. The objective of this work is to quantify the concentration of biomarkers that reaches the area of the garment where a sensor is positioned to advance the development of commercial sweat-analysing garments.Design/methodology/approachComputational analysis of the microfluidic transport of biomarkers within eccrine sweat glands provides a powerful way to explore the potential for quantitative measurements of biomarkers that can be related to the health and/or the physical activity parameters of an individual. The numerical modelling of sweat glands and the interaction of sweat with a textile layer remain however rather unexplored. This work presents a simulation of the production of sweat in the eccrine gland, reabsorption from the dermal duct into the surrounding skin and diffusion within an overlying garment.FindingsThe model represents satisfactorily the relationship between the biomarker concentration and the flow rate of sweat. The biomarker distribution across an overlying garment has also been calculated and subsequently compared to the minimum amount detectable by a sensor previously reported in the literature. The model can thus be utilized to check whether or not a given sensor can detect the minimum biomarker concentration threshold accumulated on a particular type of garment.Originality/valueThe present work presents to the best of our knowledge, the earliest numerical models of the sweat gland carried out so far. The model describes the flow of human sweat along the sweat duct and on to an overlying piece of garment. The model considers complex phenomena, such as reabsorption of sweat into the skin layers surrounding the duct, and the structure of the fibres composing the garment. Biomarker concentration maps are obtained to check whether sensors can detect the threshold concentration that triggers an electric signal. This model finds application in the development of smart textiles.

Vertical textile epifluidics for integrated real-time electrochemical sweat analysis

“…[22] Moreover, several studies have been carried out to better understand how to control and optimize the liquid absorption in porous wearable materials, which is governed by complex phenomena that can signi cantly in uence the sensing outcomes. Computational analysis of a modelled knitted fabric can quantify the concentration of sweat biomarkers at the level of a garment's absorbing surface, [24] numerical models can describe the interfacial transport on super-hydrophobic fabrics, and theoretical derivations can calculate the minimum ow resistance and nodal distance to design a fractal fabric sweat collector. [19][22] Simulation tools can reveal fundamental mechanisms of capillary-driven ows and guide the design thinking process for wearable micro uidics.…”