Functional nanotube-based textiles: Pathway to next generation fabrics with enhanced sensing capabilities

With a surge in technological advancements and the needs of diverse communities such as consumers, military and navy, the textile industry is shifting its focus to fabrication of next-generation textiles that not only meet the basic conventional requirements, but also serve a host of other functions. In this pursuit of fabricating next-generation textiles, called here e-textiles (electronic textiles), a novel technique is presented to produce nanocomposite fabrics made from carbon nanotubes (CNTs) with enhanced sensing capabilities. Catering to the ever increasing demand of improved sensors, this work discusses the electrospinning fabrication scheme that has been employed to develop novel CNT-based piezoelectric strain sensors. The resulting sensors have been characterized by performing structural vibration experiments to evaluate their strain-sensing performance. When these new CNT-based piezopolymer composites are electrospun into smart fabrics, the strain-sensing ability (as measured by voltage across the sensor) is increased by a dramatic 35 times, from 2.4 to 84.5 mV for 0.05 wt % of the nanotubes. The dominant mechanism responsible for such improvement is found to be the alignment of dipoles in the piezoelectric material. Such alignment is mainly attributed due to ability of the electrospinning process to generate very thin fibers from polymer-nanotube solution. The direct and reverse conversion of electrical energy into mechanical energy in the proposed sensors can create a platform for developing next-generation smart fabric with applications in membrane structures, distributed shape modulation and energy harvesting.