Scalable and Facile Preparation of Highly Stretchable Electrospun PEDOT:PSS@PU Fibrous Nonwovens toward Wearable...

Flexible and stretchable conductive textiles are highly desired for potential applications in wearable electronics. This study demonstrates a scalable and facile preparation of all-organic nonwoven that is mechanically stretchable and electrically conductive. Polyurethane (PU) fibrous nonwoven is prepared via the electrospinning technique; in the following step, the electrospun PU nonwoven is dip-coated with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). This simple method enables convenient preparation of PEDOT:PSS@PU nonwovens with initial sheet resistance in the range of 35-240 Ω/sq (i.e., the electrical conductivity in the range of 30-200 S m^-1) by varying the number of dip-coating times. The resistance change of the PEDOT:PSS@PU nonwoven under stretch is investigated. The PEDOT:PSS@PU nonwoven is first stretched and then released repeatedly under certain strain (denoted as prestretching strain); the resistance of PEDOT:PSS@PU nonwoven becomes constant after the irreversible change for the first 10 stretch-release cycles. Thereafter, the resistance of the nonwoven does not vary appreciably under stretch as long as the strain is within the prestretching strain. Therefore, the PEDOT:PSS@PU nonwoven can be used as a stretchable conductor within the prestretching strain. Circuits using sheet and twisted yarn of the nonwovens as electric conductors are demonstrated.