MWCNT enabled smart textiles based flexible and wearable sensor for human motion and humidity monitoring

In the study, we present a simple MWCNT enhanced textile based wearable device which can measure the change in human body motion as well as humidity of the environment for practical applications. Multiwalled carbon nanotube modified textile was fabricated by spray layer by layer method. Morphology, structure, thermal and conductive properties of the MWCNT modified textiles were investigated. The resistance of MWCNT network on textile could be controlled in a wide range from 100 MOhm to 2 KOhm by varying the concentration (1 mg/mL to 5 mg/mL) and a number of spray coating of MWCNT. The fabricated MWCNT enhanced textile sensors were attached to various human body parts (such as forehead, cheek, neck, abdomen, wrist, elbow, knee, wrist) and change in resistance pertaining to human body motion was measured. The wrist movement shows a decrease in the sensor resistance and elbow movement shows an increase in the resistance depends upon forward and reverse (due to compression and expansion of MWCNT junction network) bending of MWCNT coated fabric sensor. Further, the smart fabric was applied to monitor a wide range of humidity (RH = 19–93%) at room temperature. The sensor show high response for relative humidity (RH) of 57% with quick response (4 ± 2 s) and recovery times (14 ± 2 s) at room temperature. The change in resistance of the sensor on exposure to humidity could be attributed to the interaction of water molecules with surface (COOH, and OH) functional groups on MWCNT. The present results could be interesting for the development of simple, large scale and low cost textile based wearable sensors for multifunctional sensing applications. Graphical abstract