Digital Light 3D Printing of PEDOT-Based Photopolymerizable Inks for Biosensing
Naroa Lopez-Larrea1, Miryam Criado-Gonzalez1, Antonio Dominguez-Alfaro1
1POLYMAT, University of the Basque Country UPV/EHU, Paseo Manuel de Lardizabal 3, 20018 San Sebastián, Spain.
ACS Applied Polymer Materials
|September 19, 2022
Summary
Researchers developed new 3D printable conductive hydrogels using poly(3,4-ethylenedioxythiophene) (PEDOT) for advanced bioelectronic devices. These flexible hydrogels offer improved biosensing and long-term bioelectrode activity for health monitoring.
Area of Science:
- Materials Science
- Biomedical Engineering
- Polymer Chemistry
Background:
- 3D conductive polymers and hydrogels are crucial for interfacing electronics with biological systems.
- Developing printable, biocompatible conductive materials is essential for advanced bioelectronic devices.
- Poly(3,4-ethylenedioxythiophene) (PEDOT) is a promising conductive polymer for various applications.
Purpose of the Study:
- To optimize short-time photopolymerizable conductive inks for Digital Light 3D Printing (DLP).
- To fabricate flexible, shape-defined conductive hydrogels and dry PEDOTs.
- To evaluate the performance of these materials as bioelectrodes for biosensing and health monitoring.
Main Methods:
- Formulation of conductive inks using PEDOT:polystyrene sulfonate (PSS) in an aqueous matrix with poly(ethylene glycol) diacrylate (PEGDA) of varying molecular weights.
- Optimization of inks for Digital Light 3D Printing (DLP) technology.
- Characterization of printability, mechanical properties, conductivity, and swelling behavior of the printed materials.
Main Results:
- Achieved short-time (5 s) photopolymerization for rapid 3D printing.
- Demonstrated increased printability resolution with higher PEGDA molecular weight.
- Developed conductive hydrogels with skin-like mechanical properties (∼3 MPa Young's modulus) and good conductivity (10⁻² S cm⁻¹).
- Printed PEDOT-based hydrogels showed long-term bioelectrode activity (up to 2 weeks) for ECG and EMG recordings, outperforming commercial Ag/AgCl electrodes.
Conclusions:
- Optimized photopolymerizable PEDOT inks enable the fabrication of high-resolution, flexible conductive hydrogels via DLP.
- The developed hydrogels possess suitable mechanical and electrical properties for bioelectronic applications.
- These PEDOT-based hydrogels show significant potential as advanced bioelectrodes for enhanced biosensing and long-term health monitoring.
