Smart facemask for wireless CO2 monitoring Escobedo Araque, Pablo Fernández Ramos, María Dolores López Ruiz, Nuria Moyano-Rodríguez, Óscar Martínez Olmos, Antonio Pérez de Vargas Sansalvador, Isabel María Carvajal Rodríguez, Miguel Ángel Capitán Vallvey, Luis Fermín Palma López, Alberto José Biomedical engineering Diagnostic markers Electrical engineering Electronic Engineering Optical materials Sensors and probes This study was funded by Spanish MCIN/AEI/10.13039/501100011033/ (Projects PID2019-103938RB-I00 and ECQ2018-004937-P) and Junta de Andalucía (Projects B-FQM-243-UGR18, P18-RT-2961 and postdoctoral grant of PE DOC_00520). The projects were partially supported by European Regional Development Funds (ERDF). Source codes for microcontroller firmware (developed with MPLAB X IDE v5.45) and AndroidTM smartphone application (SmartMask v1.0) are available at an open-access repository (URI: http://hdl.handle.net/10481/71668) under a Creative Commons license. The use of facemasks by the general population is recommended worldwide to prevent the spread of SARS-CoV-2. Despite the evidence in favour of facemasks to reduce community transmission, there is also agreement on the potential adverse effects of their prolonged usage, mainly caused by CO2 rebreathing. Herein we report the development of a sensing platform for gaseous CO2 real-time determination inside FFP2 facemasks. The system con- sists of an opto-chemical sensor combined with a flexible, battery-less, near-field-enabled tag with resolution and limit of detection of 103 and 140 ppm respectively, and sensor lifetime of 8 h, which is comparable with recommended FFP2 facemask usage times. We include a custom smartphone application for wireless powering, data processing, alert management, results displaying and sharing. Through performance tests during daily activity and exercise monitoring, we demonstrate its utility for non-invasive, wearable health assessment and its potential applicability for preclinical research and diagnostics. 2022-01-27T11:18:43Z 2022-01-27T11:18:43Z 2022-01-10 info:eu-repo/semantics/article Escobedo, P., Fernández-Ramos, M.D., López-Ruiz, N. et al. Smart facemask for wireless CO2 monitoring. Nat Commun 13, 72 (2022). [https://doi.org/10.1038/s41467-021-27733-3] http://hdl.handle.net/10481/72518 10.1038/s41467-021-27733-3 eng http://creativecommons.org/licenses/by-nc-nd/3.0/es/ info:eu-repo/semantics/openAccess Atribución-NoComercial-SinDerivadas 3.0 España Springer Nature