Electrospun Mats of Thermoplastic Polyurethane and Carbon Nanotubes with Piezoresistive Behavior

Electromechanical sensors obtained by electrospun mats have a high surface area and porosity, allowing superior flexibility and sensitivity of response to the sensor. Based on this context, in this work, electrospun mats based on thermoplastic polyurethane (TPU) and multi-wall carbon nanotubes (MWCNTs) are produced by electrospinning. The electrical resistivity under different compressive stress levels is evaluated in recurring loading and unloading cycles. Incorporating MWCNT increases the elastic modulus and thermal stability but does not significantly increase the electrical conductivity. However, the electrospun mats with different concentrations of MWCNT show variation in electrical resistivity under compressive stress. The response is stable with a compressive stress of 0.25 MPa and five cycles of compression and decompression, with a variation in the relative resistivity of approximately −0.8 for all MWCNT concentrations. A similar response is observed with the increasing of the compressive stress to 0.5 MPa.