Summary

Conductive hydrogels require tunable mechanical properties, high electrical conductivity, and complex 3D structures to achieve advanced functionality in (bio)applications. Here, we design a facile strategy to construct 3D conductive hydrogels via poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS)-enriched aqueous inks within programmable printing oils. In this liquid-in-liquid printing method, the assembly of PEDOT:PSS colloidal particles from the aqueous phase and polydimethylsiloxane surfactant from the other phase forms an elastic film at the liquid-liquid interface, thereby trapping the hydrogel precursor ink in a designed 3D non-equilibrium shape for subsequent gelation and/or chemical crosslinking. In two interpenetrating hydrogel networks, the conductivity was as high as 301 S m−1 when the content of PEDOT:PSS was as low as 9 mgmL−1. The facile printability allows us to tune the composition and mechanical properties of the hydrogels, thereby facilitating the use of these conductive hydrogels as electro-microfluidic devices and, in the future, customized near-field communication (NFC) implantable biochips.

图文导读

Figure 1: 3D printing of hydrogels with tunable morphology, mechanical properties, and electrical conductivity.

Figure 2: PPS interface assembly for aqueous dispersion of PEDOT:PSS in printing oil.

Figure 3: Printed PEDOT hydrogels with chemically crosslinked networks.

Figure 4: Printed PEDOT hydrogel with two interpenetrating networks.

Figure 5: Printing of conductive hydrogels with 3D structures.

Figure 6: PEDOT conductive hydrogel as an electrochemical microfluidic device.