Evaluation and optimization of wearable microfluidic devices for sweat analysis

• Grant number: 25/06177-7
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: September 15, 2025
• End date: January 14, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Laís Canniatti Brazaca
• Grantee: Isadora Muriana de Arêa Lima Pereira
• Supervisor: Juliane Renata Sempionatto Moreto
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Rice University, United States
• Associated to the scholarship: 23/15245-0 - Wearable lateral flow device for the colorimetric determination of Dermicidin in sweat, BP.IC

Abstract

Wearable biosensors are an emerging trend in analytical chemistry, enabling real-time, non-invasive monitoring of analytes in various biofluids. While existing devices analyze tears, sweat, and saliva, they are primarily limited to detecting electrolytes, small molecules, or electrochemically active compounds like glucose and lactate. Notably, wearable biosensors for specific protein biomarkers in sweat remain unexplored, despite their potential for non-invasive diagnosis of diseases such as cancer, neuropathies, and infections. To enable precise protein biomarker analysis in sweat, a microfluidic device must be designed to accommodate variable sweat flow rates while minimizing contamination and preventing sample evaporation. The microfluidic device currently produced by the candidate in Brazil is fabricated using double-sided adhesives - cut with CO2 laser - with paper membranes attached covered by a plastic film layer. Although this device showed promising results in in vitro tests, some limitations were observed that may affect the precise analysis in sweat, such as reverse and inconsistent fluid flow, as well as variability between devices due to manual assembly. In this context, this project aims to develop, evaluate and optimize microfluidic devices using various fabrication techniques, including laser engraving, laser cutting and soft lithography. The developed devices will be evaluated through in vitro tests using flow rates comparable to human sweat and, depending on ethical committee approval, through on-body experiments. By the end of this project, we aim to develop a robust microfluidic device to be used along with the lateral flow colorimetric wearable biosensor that is being developed by the candidate in Brazil. We expect the biosensor to be able to analyze specific proteins in sweat samples with high precision and efficiency. (AU)