title: Paper-Based Electrical Respiration Sensor.
abstract: Current methods of monitoring breathing require cumbersome, inconvenient, and often expensive devices; this requirement sets practical limitations on the frequency and duration of measurements. This article describes a paper-based moisture sensor that uses the hygroscopic character of paper (i.e. the ability of paper to adsorb water reversibly from the surrounding environment) to measure patterns and rate of respiration by converting the changes in humidity caused by cycles of inhalation and exhalation to electrical signals. The changing level of humidity that occurs in a cycle causes a corresponding change in the ionic conductivity of the sensor, which can be measured electrically. By combining the paper sensor with conventional electronics, data concerning respiration can be transmitted to a nearby smartphone or tablet computer for post-processing, and subsequently to a cloud server. This means of sensing provides a new, practical method of recording and analyzing patterns of breathing.
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: Firat
authors.initials: F
authors.lastname: Güder
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: Alar
authors.initials: A
authors.lastname: Ainla
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: Julia
authors.initials: J
authors.lastname: Redston
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: Bobak
authors.initials: B
authors.lastname: Mosadegh
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Glavan
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Martin
authors.affiliation: Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA, 02138, USA. gwhitesides@gmwgroup.harvard.edu.|Wyss Institute for Biologically Inspired Engineering, Harvard University, 60 Oxford Street, Cambridge, MA, 02138, USA. gwhitesides@gmwgroup.harvard.edu.
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides
mesh_terms: D004560:Electricity; D015444:Exercise; D006801:Humans; D006813:Humidity; D008991:Monitoring, Physiologic / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D010209:Paper; D012119:Respiration; D012815:Signal Processing, Computer-Assisted; D000068997:Smartphone; D059015:Wireless Technology
keywords: digital health; internet of things; paper; respiration; sensors