Directional Anchoring Doping Networks for Robust Polymeric Bioelectronics.

Area of Science:

• Bioelectronics
• Materials Science
• Polymer Chemistry

Background:

• Achieving high electrical conductivity and stretchability simultaneously in conductive polymers is a major challenge for bioelectronics.
• Existing materials often compromise one property for the other, limiting their application in wearable and implantable devices.

Purpose of the Study:

• To develop a novel molecular design strategy for conductive polymers that decouples electrical conductivity and stretchability.
• To create a highly conductive and stretchable polymer composite for advanced bioelectronic interfaces.

Main Methods:

• An "anchoring-buffering" molecular design strategy using in situ polymerizable hydroxyalkyl acrylate (HAX) dopants in poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT: PSS).
• Systematic variation of alkyl chain lengths in HAX dopants (HA0 to HA4) to optimize doping efficiency and π-stacking.
• Fabrication and characterization of composite films for electrical conductivity and mechanical stretchability measurements.

Main Results:

• The developed composite film achieved exceptional performance with 850 S/cm conductivity and 88% elongation, surpassing existing stretchable conductive polymers.
• The "anchoring-buffering" design optimized electrostatic screening and π-stacking, maintaining conjugation pathways and dissipating strain.
• Integrated electrodes demonstrated stable electrophysiological signal acquisition (EMG/ECG/EEG) and 99.5% gesture recognition accuracy after 24 hours of wear.

Conclusions:

• The "anchoring-buffering" molecular design strategy effectively decouples conductivity and stretchability in conductive polymers.
• This approach provides a general framework for developing next-generation wearable and implantable bioelectronic devices.
• The optimized PEDOT: PSS composite offers a promising material for conformal biointerfaces with long-term stability.