Flexible, Highly Sensitive Paper-Based Screen Printed MWCNT/PDMS Composite Breath Sensor for Human Respiration Monitoring

Abstract

Accurate measurement and monitoring of respiration is vital in patients affected by severe acute respiratory syndrome coronavirus -2 (SARS-CoV-2). Patients with severe chronic diseases and pneumonia need continuous respiration monitoring and oxygenation support. Existing respiratory sensing techniques require direct contact with the human body along with expensive and heavy Holter monitors for continuous real-time monitoring. In this work, we propose a low-cost, non-invasive and reliable paper-based wearable screen printed sensor for human respiration monitoring as an effective alternative of existing sensing systems. The proposed sensor was fabricated using traditional screen printing of multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) composite based interdigitated electrodes on paper substrate. The paper substrate was used as humidity sensing material of the sensor. The hygroscopic nature of paper during inhalation and exhalation causes a change in dielectric constant, which in turn changes the capacitance of the sensor. The composite interdigitated electrode configuration exhibited better response times with a rise time of 1.178s being recorded during exhalation and fall time of 0.88s during inhalation periods. The respiration rate of sensor was successfully examined under various breathing conditions such as normal breathing, deep breathing, workout, oral breathing, nasal breathing, fast breathing and slow breathing by employing it in a wearable mask, a mandatory wearable product during the current COVID-19 pandemic situation.Thus, the above proposed sensor may hold tremendous potential in wearable/flexible healthcare technology with good sensitivity, stability, biodegradability and flexibility at this time of need.

Polyimide-Based High-Performance Film Bulk Acoustic Resonator Humidity Sensor and Its Application in Real-Time Human Respiration Monitoring

“…The same is true in reality; subjects 3 and 4 swam or exercised about 5 times a week, while subject 2 only exercised almost once a week. In any case, all five subjects in our experiment were fitter than the subject in reference [ 35 ], since the BI calculated of subject in our experiment is much smaller than that of subject in reference [ 35 ], which reached 3.37. Results showed that both the resonant frequency and reflection coefficient S 11 can be used to efficiently predict the fitness of individual, especially for athletes.…”

A sensitive and flexible interdigitated capacitive strain gauge based on carbon nanofiber/PANI/silicone rubber nanocomposite for body motion monitoring

“…In another study, an interdigitated electrode strain gauge was reported by a gauge factor of around 8.24, which was fabricated by conventional screen printing of multiwalled carbon nanotubes and PDMS composite on a paper substrate. Although the gauge factor of the capacitive strain gauge has been improved, the stretchability is not enough for human motion detection, and it would be applicable for small strain detection such as human respiration detection [52].…”

A Breathable, Reusable, and Zero-Power Smart Face Mask for Wireless Cough and Mask-Wearing Monitoring

“…Perhaps, face mask wearing enforcement in densely populated places is one of the most effective means to stop the spread of virus, as respiratory face masks are highly effective in blocking most respiratory droplets and aerosols. , Despite these efforts, the increase in reported cases of COVID-19 continues, which has led to an urgent need for more effective ways to combat the coronavirus and restore society to a certain semblance of normalcy. To address this, smart face masks made by equipping respiratory face masks with electronic sensors and modules have been recently proposed. − To date, smart masks are mainly used for two purposes: (1) to monitor respiratory symptoms, such as cough, − , and (2) to enhance the filtration of airborne pathogens including coronaviruses; ,, both contribute to prevention and control of respiratory diseases. In addition to the significance in diminishing the pandemic, there has been a witnessed trend of smart masks and wearables for their potential in health monitoring and preventive care, − personalized behavior modeling, − and healthcare internet-of-things (IoTs). − Nevertheless, existing research largely ignores wearing comfort and breathability, which are crucial for user experience and compliance of wearing face masks.…”

“…The proposed smart face mask consists of a zero-power radio frequency (RF) harmonic transponder, which is attached to the inner side of an ordinary face mask and can be torn off and reattached for repeated usage (Figure b). To achieve better wearing comfort than current smart masks, − ,, the RF harmonic transponder is printed using spray-printed silver nanowires (AgNWs) on the multiscale porous polystyrene- block -poly­(ethylene- ran -butylene)- block -polystyrene (SEBS) substrate (Figure c); both nanomaterials are lightweight, flexible, stretchable, and, most importantly, breathable. Moreover, the 0.2–7 μm pores of the SEBS substrate can efficiently block the sunlight, while allowing transmission of the human-body infrared (IR) radiation (which is in some sense similar to a spectral filter), thereby enabling passive heat dissipation and/or passive cooling .…”

“…To address this, smart face masks made by equipping respiratory face masks with electronic sensors and modules have been recently proposed. 5−9 To date, smart masks are mainly used for two purposes: (1) to monitor respiratory symptoms, such as cough, [5][6][7]10 and (2) to enhance the filtration of airborne pathogens including coronaviruses; 8,9,11 both contribute to prevention and control of respiratory diseases. In addition to the significance in diminishing the pandemic, there has been a witnessed trend of smart masks and wearables for their potential in health monitoring and preventive care, 12−16 personalized behavior modeling, 17−20 and healthcare internetof-things (IoTs).…”