Smartphone Case-Based Gas Sensing Platform for On-site Acetone Tracking

Gas sensor-embedded smartphones would offer theopportunity of on-site tracking of gas molecules for various applications,for example, harmful air pollutant alarms or noninvasive assessment ofhealth status. Nevertheless, high power consumption and difficulty inreplacingmalfunctionedsensorsaswellaslimitedspaceinthesmartphone to host the sensor restrain the relevant advancements. Inthis article, we create a smartphone case-based sensing platform byintegrating the functional units into a smartphone case, which performs alow detection limit of 117 ppb to acetone and high specificity.Particularly, dimming glass-regulated lightfidelity (Li-Fi) communicationis successfully developed, allowing the sensing platform to operate withrelatively low power consumption (around 217 mW). Experimental proofon harmful gas sensing and potential clinic application is implementedwith the sensing platform, demonstrating satisfactory sensing performanceand acceptable health risk pre-warning accuracy (87%). Thus, the developed smartphone case-based sensing platform would be agood candidate for realizing harmful gas alarms and noninvasive assessment of health status.