Conductive bacterial cellulose/multiwall carbon nanotubes nanocomposite aerogel as a potentially flexible lightweight strain sensor

In this work, in-situ biosynthesized bacterial cellulose (BC) /multiwall carbon nanotubes (MWCNTs) nanocomposite hydrogels converted to the conductive nanocomposite aerogels via the supercritical CO2 method. A low percolation threshold value of 0.0041 (volume concentration) predicted for BC/MWCNTs nanocomposite aerogels by the proposed modified model. The piezoresistive behavior of the nanocomposite aerogel at percolation threshold, evaluated in tension mode. The strain sensing outcomes revealed a linear trend during loading until a critical strain, afterward began to decline with further increasing of strain. Moreover, by applying loading unloading cyclic tension for 10 times at two different strain amplitudes (2% and 8%), the variation of relative resistance was different. This attributed to the rearrangement of MWCNTs at high strain condition. The gauge factor of 21 and response time of 390 ms obtained for flexible lightweight strain sensor. The fabricated strain sensor utilized to monitor human detection motion.