Mom and Baby Wellness with a Smart Lactation Pad: A Wearable Sensor‐Embedded Lactation Pad for on‐Body Quantification of Glucose in Breast Milk

Wearable sensors are transforming healthcare by facilitating rapid, non-invasive, on-body biochemical analysis in biofluids such as sweat, tears, saliva, and blood, providing real-time insights into health conditions. Despite extensive academic and industrial efforts in developing wearable devices, very few are tailored to meet women's health needs. None are specifically designed for measurements in human breast milk. Beyond being the optimal source of infant nutrition, milk serves as a rich biofluid containing potential biomarkers reflecting a mother's health as well. Analyzing the composition of milk offers valuable information for the health of the infant, and the mother. This work pioneers a wearable sensor embedded in a lactation pad for on-body sampling of breast milk and continuous analysis of glucose levels in breast milk. Lactation pads are worn by most lactating individuals to absorb milk leakage during the day, and keep the cloth dry. In this work, by integrating microfluidic channels and electrochemical sensors in the lactation pad, milk sampling and analysis becomes part of an existing daily routine for the mother, posing no additional burden for milk sampling and analysis. The electrochemical sensors are developed using laser-induced carbonization of polyimide thin films, allowing for development of flexible, low-cost, and high-surface area electrodes. Glucose sensing is done via an enzymatic membrane composed of glucose oxidase, glutaraldehyde, bovine serum albumin, and Nafion to achieve enhanced enzyme protection and extended biosensor shelf life and operation in milk. Notably, the wearable device demonstrates high accuracy (96.8 to 104.1%) in measurement of glucose in whole undiluted human milk, collected 1st, 6th, and 12th months postpartum. This innovative smart lactation pad empowers mothers to track their babies' glucose intake and potentially identify early signs of health concerns.