New Insights to Design Electrospun Fibers with Tunable Electrical Conductive-Semiconductive Properties

Abstract

Fiber electronics, such as those produced by the electrospinning technique, have an extensive range of applications including electrode surfaces for batteries and sensors, energy storage, electromagnetic interference shielding, antistatic coatings, catalysts, drug delivery, tissue engineering, and smart textiles. New composite materials and blends from conductive-semiconductive polymers (C-SPs) offer high surface area-to-volume ratios with electrical tunability, making them suitable for use in fields including electronics, biofiltration, tissue engineering, biosensors, and "green polymers". These materials and structures show great potential for embedded-electronics tissue engineering, active drug delivery, and smart biosensing due to their electronic transport behavior and mechanical flexibility with effective biocompatibility. Doping, processing methods, and morphologies can significantly impact the properties and performance of C-SPs and their composites. This review provides an overview of the current literature on the processing of C-SPs as nanomaterials and nanofibrous structures, mainly emphasizing the electroactive properties that make these structures suitable for various applications.

Keywords: biointegration; conducting polymers; conductive fiber-based structures; electrospinning; fiber electronics; semiconducting polymers.

Figure 1

Electrospun nanofibers containing C-SPs: main applications for electronic devices and biological purposes.

Figure 2

Schematic of fundamental steps that characterize the preparation of electrospun fibers via electrospinning technique. Solution preparation (a) and spinning essential variables (b).

Figure 3

P- and n-type coaxial nanofiber semiconducting polymers formed as a nanofiber provide an opportunity for the formation of a p-n junction that can be chained for electroactive textiles and single nanofiber devices. Reprinted from [64].

Figure 4

Fabricated electrospun continuous coaxial nanofiber–p-n junctions. The shell/sheath is formed by the BBL solution (a, blue) and covers the P3HT/PS solution (b, red) core. An electric field overcomes the surface tension, forming nanofibers. Inset: (c) diode symbols representing the continuous heterojunction formed between the core and the shell. (d,e) Formed coaxial nanofibers where BBL covers the P3HT/PS core. Adapted with permission from [64].

Figure 5

Schematic diagram illustrating the steps involved in the fabrication of PVA-GO/PEDOT nanofibers prepared by combining electrospinning and electropolymerization methods. Adapted with permission from [65]. Copyright 2019 American Chemical Society.

Figure 6

Semiconductive composite nanofibers. PVDF-TrFE/PEDOT (a), PLA/PANI (b), PLA/P3HT (c), and core–shell P3HT/BBL (d). Adapted with permission from [64,66,67,68].

Figure 7

PVDF-TrFE/P3HT composite nanofibers for molecular adsorption. Inset (a) Unloaded (−P3HT) (A) and loaded (+P3HT) (B) nanofibers without (a) and with (b) the application of an external electric field. Inset (b): Schematic of the nanofibers system for controlled adsorption. Adapted with permission from [76].

Figure 8

Schematic description of shape/volume fraction effect of ultrafine short fibers on the transfer mechanisms of electrical signals for in vitro cell interactions. Adapted with permission from [88].

Figure 9

(A) Schematic illustration of the preparation of P3HT micro/nanofibers and P3HT-patterned surface for PC12 cell culture. (B) UV-vis absorption spectra of P3HT polymer in anisole solution, P3HT micro/nanofiber, and homogeneous films. (C,D) Digital photographs of P3HT in hot anisole (100 °C) (C) and after being cooled to 25 °C (D). Reprinted with permission from ref. [93]. Copyright 2022 American Chemical Society.

Figure 10

SEM images of 3 wt % PLA/PANI-CSA (a) and single nanofiber sensing device (b). Sensor characterization of alcohol vapors (c). Response and recovery times for each alcohol (d). Adapted with permission from ref. [107].