Inkjet and extrusion printing of conducting poly(3,4-ethylenedioxythiophene) tracks on and embedded in biopolymer materials

Abstract

Two printing methods, extrusion and inkjet, are used to deposit tracks of PEDOT/PSS conducting polymer onto biopolymer films with a view to prepare implantable tissue mimics containing electronic devices. Extruded tracks offer lower printing resolution, but better electrical characteristics compared to inkjet printed tracks. The biopolymer-ink interaction results in narrower printed tracks compared to those on glass. This affects the final conductivity, which is lower for printed tracks on biopolymer than for lines printed on glass, due to the part of the track lying below the surface. Extrusion printing is used to embed tracks into a biopolymer matrix, resulting in significant improvement in electrical characteristics. The electrical conductivity of embedded tracks (17 S cm1) is an order of magnitude higher than for track deposition on the surface of biopolymer film and 3 times higher than for tracks on glass.

Poly(3,4-ethylenedioxythiophene):dextran sulfate (PEDOT:DS) – A highly processable conductive organic biopolymer

“…Extrusion printing of a viscous aqueous suspension of PEDOT:DS was performed using a custom printer based on a modified computer numerically controlled (CNC) milling machine [21] (Sherline Products, CA). In brief, the system was equipped with a three-axis positioning platform and was controlled by the manufacturer's EMC2 software interface.…”

Tissue engineering with gellan gum

“…Carbon nanotubes 97,98 , carbon nanofibers 99 organic conducting polymers 99,100 , and graphene 71 , have all been successfully dispersed into GG systems, whilst gellan gum has also been used as a dopant for electropolymerised conductive polymer surfaces for neural electrodes 101 . To date, there are few examples of conductive GG systems being applied in vivo towards clinical application, however the systems have generally appeared most promising when applied as electrode surfaces with low water content, rather than as water-swollen hydrogels.…”

Next generation bioelectronics: Advances in fabrication coupled with clever chemistries enable the effective integration of biomaterials and organic conductors

“…58,59 ICPs are also highly amenable to a range of material fabrication techniques that can be used to fashion two- 60 and three-dimensional structures, 61 thus providing a dynamic and powerful biomaterial platform that may be applied to a suite of diverse bioapplications. These organic conductors will form the focus of this research update.…”

“…Inkjet and extrusion printing have been used to print parallel tracks of PEDOT-PSS on both glass and a biopolymer substrate. 61 Extrusion printing was successfully employed to embed PEDOT-PSS tracks into a biopolymer matrix of chitosan and hyaluronic acid, with the embedded PEDOT structures demonstrating good conductivity. This technique was proposed as promising method to introduce patterned organic conductors into biopolymer gels for use in a range of bionic applications and devices.…”