Epidermal tattoo potentiometric sodium sensors with wireless signal transduction for continuous non-invasive sweat monitoring

• Published in: Biosensors & bioelectronics Vol. 54; pp. 603 - 609
• Main Authors: Bandodkar, Amay J., Molinnus, Denise, Mirza, Omar, Guinovart, Tomás, Windmiller, Joshua R., Valdés-Ramírez, Gabriela, Andrade, Francisco J., Schöning, Michael J., Wang, Joseph
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.04.2014; Elsevier
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; biosensors; Biotechnology; deformation; electrolytes; Epidermal electronics; Equipment Design; Exercise; Fundamental and applied biological sciences. Psychology; health services; Humans; Ion selective electrode; Ion-Selective Electrodes; monitoring; Potentiometry - instrumentation; Screen printing; signal transduction; sodium; Sodium - analysis; Sodium - metabolism; sweat; Sweat - chemistry; Sweat - metabolism; Sweat sodium; Wireless electronics; Wireless Technology - instrumentation; Screen printing; Ion selective electrode; Sweat sodium; Epidermal electronics; Wireless electronics; Electronics; Potentiometry; Continuous process; Signal transduction; Detector; Sodium; Non invasive method; Monitoring
• ISSN: 0956-5663; 1873-4235; 1873-4235
• DOI: 10.1016/j.bios.2013.11.039

This article describes the fabrication, characterization and application of an epidermal temporary-transfer tattoo-based potentiometric sensor, coupled with a miniaturized wearable wireless transceiver, for real-time monitoring of sodium in the human perspiration. Sodium excreted during perspiration is an excellent marker for electrolyte imbalance and provides valuable information regarding an individual's physical and mental wellbeing. The realization of the new skin-worn non-invasive tattoo-like sensing device has been realized by amalgamating several state-of-the-art thick film, laser printing, solid-state potentiometry, fluidics and wireless technologies. The resulting tattoo-based potentiometric sodium sensor displays a rapid near-Nernstian response with negligible carryover effects, and good resiliency against various mechanical deformations experienced by the human epidermis. On-body testing of the tattoo sensor coupled to a wireless transceiver during exercise activity demonstrated its ability to continuously monitor sweat sodium dynamics. The real-time sweat sodium concentration was transmitted wirelessly via a body-worn transceiver from the sodium tattoo sensor to a notebook while the subjects perspired on a stationary cycle. The favorable analytical performance along with the wearable nature of the wireless transceiver makes the new epidermal potentiometric sensing system attractive for continuous monitoring the sodium dynamics in human perspiration during diverse activities relevant to the healthcare, fitness, military, healthcare and skin-care domains. •A non-invasive epidermal tattoo-based sodium sensor is presented.•The device is resilient towards mechanical deformations experienced by human epidermis.•On-body wireless real-time monitoring of sodium dynamics in sweat during physical activity is illustrated.