Pencil-drawn Paper-based Non-invasive and Wearable Capacitive Respiration Sensor

This paper describes a fully-drawn pencil-on-paper based low-cost capacitive sensor for non-invasive respiration monitoring. The sensor utilizes the hygroscopic character of the paper to measure the breathing rate and pattern. The adsorption and desorption of water molecules on paper during inhalation and exhalation results in variation in its dielectric constant. This change in dielectric constant during respiration reflects the change in capacitance of the sensor. By interfacing the sensor with the microcontroller, the capacitance data was acquired and transferred to a smartphone through Bluetooth communication. Being a low cost, wearable, non-invasive and disposable sensor, it holds tremendous potential in healthcare technology and can be commercialized into a viable product for easy-to-use diagnostic purpose.