Issue 10, 2023

Stable organic electrochemical neurons based on p-type and n-type ladder polymers


Organic electrochemical transistors (OECTs) are a rapidly advancing technology that plays a crucial role in the development of next-generation bioelectronic devices. Recent advances in p-type/n-type organic mixed ionic-electronic conductors (OMIECs) have enabled power-efficient complementary OECT technologies for various applications, such as chemical/biological sensing, large-scale logic gates, and neuromorphic computing. However, ensuring long-term operational stability remains a significant challenge that hinders their widespread adoption. While p-type OMIECs are generally more stable than n-type OMIECs, they still face limitations, especially during prolonged operations. Here, we demonstrate that simple methylation of the pyrrole-benzothiazine-based (PBBT) ladder polymer backbone results in stable and high-performance p-type OECTs. The methylated PBBT (PBBT-Me) exhibits a 25-fold increase in OECT mobility and an impressive 36-fold increase in μC* (mobility × volumetric capacitance) compared to the non-methylated PBBT-H polymer. Combining the newly developed PBBT-Me with the ladder n-type poly(benzimidazobenzophenanthroline) (BBL), we developed complementary inverters with a record-high DC gain of 194 V V−1 and excellent stability. These state-of-the-art complementary inverters were used to demonstrate leaky integrate-and-fire type organic electrochemical neurons (LIF-OECNs) capable of biologically relevant firing frequencies of about 2 Hz and of operating continuously for up to 6.5 h. This achievement represents a significant improvement over previous results and holds great potential for developing stable bioelectronic circuits capable of in-sensor computing.

Graphical abstract: Stable organic electrochemical neurons based on p-type and n-type ladder polymers

Supplementary files

Article information

Article type
05 Jun 2023
13 Jul 2023
First published
15 Jul 2023
This article is Open Access
Creative Commons BY license

Mater. Horiz., 2023,10, 4213-4223

Stable organic electrochemical neurons based on p-type and n-type ladder polymers

H. Wu, J. Huang, S. Y. Jeong, T. Liu, Z. Wu, T. van der Pol, Q. Wang, M. Stoeckel, Q. Li, M. Fahlman, D. Tu, H. Y. Woo, C. Yang and S. Fabiano, Mater. Horiz., 2023, 10, 4213 DOI: 10.1039/D3MH00858D

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