Inkjet-Printed, Flexible Organic Electrochemical Transistors for High-Performance Electrocorticography Recordings

Area of Science:

• Bioelectronics
• Materials Science
• Neuroscience

Background:

• Organic electrochemical transistors (OECTs) are promising for biosignal amplification, including electrocorticography (ECoG).
• Current OECT fabrication methods are complex, limiting their accessibility and scalability for widespread use.

Purpose of the Study:

• To introduce a novel, high-performance, all-planar, all-printed OECT device for enhanced ECoG recording accuracy and sensitivity.
• To demonstrate a simplified, cost-effective fabrication process for OECTs suitable for flexible substrates.

Main Methods:

• Development of a three-step drop-on-demand inkjet printing process for OECT fabrication on flexible substrates.
• Optimization of in-plane gate voltage control for operation at peak transconductance.
• In vivo evaluation using a rat seizure model to assess ECoG recording performance.

Main Results:

• The inkjet-printed OECTs exhibit a rapid response time (0.5 ms), small channel area (1950 μm²), and high transconductance (11 mS).
• Optimized gate control increased the signal-to-noise ratio (SNR) by up to 133%.
• In vivo tests showed superior performance compared to conventional electrodes, achieving an SNR of 48 dB in seizure recordings.

Conclusions:

• Inkjet-printed OECTs offer a scalable and accessible platform for high-fidelity biosignal recording.
• This technology has the potential to improve diagnostic tools for timely detection of neurological conditions, enhancing patient care.
• The simplified fabrication process reduces costs and complexity, paving the way for broader clinical applications.