Seminar

Hyo-Ryoung Lim
Major of Human Biocovergence, Division of Smart Healthcare, College of Information Technology
and Convergence, Pukyong National University, Busan, Korea

Monitoring electrolytes is critical for newborns and babies in the intensive care unit. However, the gold standard
methods use a blood draw, which is painful and only offers discrete measures. Although salivary-based detection
offers promise as an alternative, existing devices are ineffective for real-time, continuous monitoring of
electrolytes due to their rigidity, bulky form factors, and lack of salivary accumulation. Here, we introduce a
smart, wireless, bioelectronic pacifier for salivary electrolyte monitoring of neonates, which can detect real-time
continuous sodium and potassium levels without a blood draw. The miniature system facilitates the seamless
integration of the ultralight and low-profile device with a commercial pacifier without additional fixtures or
structural modifications. The portable device includes ion-selective sensors, flexible circuits, and microfluidic
channels, allowing simplified measurement protocols in non-invasive electrolyte monitoring. The flexible
microfluidic channel enables continuous and efficient saliva collection from a mouth. By modifying the surface
properties of the channels and the structure of the capillary reservoir, we achieve reliable pumping of the viscous
medium for quick calibration and measurement. Embedded sensors in the system show good stability and
sensitivity: 52 and 57 mV/decade for the sodium and potassium sensor, respectively. In vivo study with neonates
in the intensive care unit captures the device’s feasibility and performance in the natural saliva-based detection
of the critical electrolytes without induced stimulation