High-sensitive MwCNTs/CMC/PDMS flexible capacitive pressure sensor prepared through ice template method and its wearable applications

In recent years, pressure sensors with high sensitivity and flexibility have been widely used in the fields of wearable electronics, soft robots, medical monitoring, and so on. In this paper, a through-hole structure comprising of multi-walled carbon nanotubes (MwCNTs)/carboxymethyl cellulose (CMC)/polydimethylsiloxane (PDMS) was constructed through an ice template method and then it functioned as the dielectric layer of a newly made flexible capacitive pressure sensor. The sensitivity, stability, response time, and human applicability of the sensor were fully studied. The experimental method with ice template has the advantages of environmental protection and safety. More importantly, through the regulation of chemical composition, the porous sponge can have a specific pore morphology. The experimental e results showed that the dielectric layer with a through-hole structure had been built successfully and the PDMS resin was impregnated into the through-hole structure. The MwCNTs/CMC/PDMS capacitive pressure sensor possessed a high sensitivity (~ 2.143 kPa −1 ) and good stability in the low-pressure range (0–1 kPa). Moreover, a low detection limit (~ 3 Pa) and fast response time (~ 250 ms) were obtained. Human applicability tests revealed that our flexible sensor could catch the response of the human body swiftly so that it exhibited bright application prospects in wearable electronics.