(Invited) Wearable and Point-of-Care Biosensors for Milk Analysis: Advancing Materials and Devices for Women’s Health

Wearable and point-of-care biosensors are redefining how we monitor health by enabling rapid, non-invasive chemical analysis directly from the body. Despite their widespread emergence for applications such as sweat or saliva monitoring, very few technologies have been developed to address women’s health needs—particularly during lactation. Human milk is a dynamic and information-rich biofluid that not only nourishes infants but also reflects maternal health. Yet, tools for real-time, accessible milk analysis remain virtually nonexistent. Our work introduces a new generation of wearable and low-cost analytical devices designed specifically for monitoring biomarkers in breast milk, transforming a routine postpartum accessory into a powerful diagnostic platform. We have developed a smart lactation pad that integrates microfluidic systems and electrochemical sensors within a soft, absorbent substrate worn comfortably during the day. As milk naturally leaks and accumulates in the pad, capillary-driven microchannels direct small volumes toward embedded sensing zones for biochemical analysis. This continuous, on-body sampling approach eliminates the need for manual collection or external lab testing, providing immediate insights into both maternal and infant well-being. The system is designed to quantify key components of milk—including glucose, electrolytes, and drug residues—enabling informed feeding decisions and supporting safe medication management (“pump-and-dump” strategies). At the core of our sensing platform is laser-induced graphene (LIG), produced by direct laser engraving of polyimide films. This rapid, mask-free process converts the polymer surface into a conductive, porous, and flexible carbon network ideally suited for wearable electrochemical sensing. Surface functionalization with enzymes, ion-selective membranes, or redox mediators allows the LIG electrodes to target diverse analytes while maintaining stability in complex milk matrices. Modulation of the LIG’s surface topography and wettability further improves compatibility with sensing membranes and enhances signal reproducibility. Additionally, our calibration-free ion sensing design enables long-term, drift-free monitoring of sodium-to-potassium ratios—offering the first non-invasive, early indication of mastitis in lactating individuals. By uniting advances in materials engineering, microfluidic design, and wearable electronics, this work bridges the gap between fundamental sensor development and real-world maternal health applications. The smart lactation pad represents a scalable, user-friendly platform that brings laboratory-grade analysis to the home, empowering parents and clinicians with actionable biochemical data. Beyond milk analysis, this framework establishes a foundation for next-generation wearables that address historically overlooked needs in women’s health through accessible, personalized chemical sensing. References (1) Adv. Funct. Mater., 2025, 2420973., (2) Device, 2025, 3, 100774., (3) npj Women’s Health, 2025, 3, 48. (4) Adv. Funct. Mater. (2025): e13707. Figure 1