title: A Wearable Hydration Sensor with Conformal Nanowire Electrodes.
abstract: A wearable skin hydration sensor in the form of a capacitor is demonstrated based on skin impedance measurement. The capacitor consists of two interdigitated or parallel electrodes that are made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. The flexible and stretchable nature of the AgNW/PDMS electrode allows conformal contact to the skin. The hydration sensor is insensitive to the external humidity change and is calibrated against a commercial skin hydration system on an artificial skin over a wide hydration range. The hydration sensor is packaged into a flexible wristband, together with a network analyzer chip, a button cell battery, and an ultralow power microprocessor with Bluetooth. In addition, a chest patch consisting of a strain sensor, three electrocardiography electrodes, and a skin hydration sensor is developed for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless, and continuous monitoring of skin hydration and other health parameters.
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Yao
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Myers
authors.affiliation: Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Malhotra
authors.affiliation: Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Feiyan
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Alper
authors.initials: A
authors.lastname: Bozkurt
authors.affiliation: Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Muth
authors.affiliation: Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhu
mesh_terms: D004566:Electrodes; D006801:Humans; D053770:Nanowires; D000074267:Organism Hydration Status; D012834:Silver; D000076251:Wearable Electronic Devices; D059015:Wireless Technology
chemical_list: D012834:Silver
keywords: electrocardiogram; hydration sensing; multifunctional sensing; silver nanowires; strain sensing