Conducting Polymer Nanoparticles with Intrinsic Aqueous Dispersibility for Conductive Hydrogels

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Conductive hydrogels are crucial for interfacing biological tissues with electronic devices due to their unique ionic-electronic conduction properties.
• Existing conductive fillers for bioelectronics often lack scalability, biocompatibility, or compatibility with aqueous hydrogel systems.
• There is a need for advanced fillers that can be easily incorporated into hydrogels for bioelectronic applications.

Purpose of the Study:

• To develop intrinsically dispersible, highly conductive nanoparticles for use in bioelectronic hydrogels.
• To demonstrate the scalability and ease of processing of these novel nanoparticles.
• To evaluate the performance of these nanoparticles in printed biomedical structures.

Main Methods:

• Facile, scalable nonsolvent induced phase separation method to process acid-crystallized PEDOT:PSS nanoparticles (ncrys-PEDOTx) from commercial PEDOT:PSS.
• Incorporation of ncrys-PEDOTx into diverse aqueous biomaterial solutions and microstereolithography resins without additives or sonication.
• Characterization of particle conductivity and dispersibility, and printing of complex biomedical structures.

Main Results:

• Achieved high conductivities of up to 410 S cm⁻¹ in the ncrys-PEDOTx nanoparticles.
• Demonstrated remarkable dispersibility and homogeneous incorporation of ncrys-PEDOTx into hydrogels at high loadings without surfactants.
• Successfully printed complex biomedical structures with fine features (< 150 µm) using resins with up to 10% ncrys-PEDOTx loading.

Conclusions:

• The developed ncrys-PEDOTx nanoparticles provide a scalable, biocompatible, and plug-and-play solution for creating advanced soft organic bioelectronic materials.
• These nanoparticles overcome limitations of traditional conductive fillers, enabling easier fabrication of sophisticated bioelectronic devices.
• The findings pave the way for improved hydrogel-based interfaces in bioelectronics and medical applications.