Dynamic Bending Response and Durability of a DSTT-Fabricated MWCNT-Coated Cotton Fabric Sensor
Muhammad Shahbaz, Hiroshi FurutaReliable textile sensors must maintain a stable electrical response during repeated bending and across different bending speeds encountered in wearable use. Here, a multi-walled carbon nanotube (MWCNT)-coated cotton fabric fabricated by the drop-casting, sonication, and thermal treatment (DSTT) method was evaluated as a piezoresistive bending sensor against a room-temperature-dried (RT) control at the same coating cycle. The DSTT sensor retained 89.2% of its peak response after 1000 continuous bending cycles, compared with 20.0% for the RT control. Across sequential tests at 1, 2, 4, and 8 mm/s, the DSTT mean peak response varied by 11.1% of the grand mean while maintaining regular waveforms and baseline recovery. Carriage-separation testing gave an average regression sensitivity of approximately 0.58%/mm (R2 = 0.982–0.986) and a maximum loading-unloading difference of 8.7% of full scale. A glove-mounted DSTT sensor also produced distinct response levels at manually assigned finger positions of 0°, 45°, and 90°. For the selected specimens, these results demonstrate greater dynamic response stability for DSTT than for RT under the tested protocols, together with discrimination among manually assigned finger positions in the glove demonstration. The speeds were applied in a fixed order; therefore, the effects of bending speed and cumulative cycle history cannot be separated.