# Organic Electrochemical Transistors in Tissue‐Interfaced Bioelectronics

## TL;DR

This review discusses organic electrochemical transistors (OECTs) and their potential for long-term, stable integration with biological tissues in bioelectronics.

## Contribution

The paper provides a comprehensive review of recent advancements in OECT design, fabrication, and biological applications.

## Key findings

- OECTs offer mechanical compliance and biocompatibility, making them suitable for interfacing with soft biological tissues.
- Strategies like molecular functionalization and mechanical matching improve OECT performance in dynamic physiological conditions.
- Challenges remain in biocompatibility and minimizing foreign body response for in vivo applications.

## Abstract

Organic electrochemical transistors (OECTs) have attracted considerable attention in the field of tissue‐interfaced bioelectronics. They uniquely bridge the ionic and electronic domains while offering mechanical compliance, biocompatibility, and high signal amplification. These characteristics make them especially advantageous for applications requiring stable, long‐term integration with soft, deformable, and dynamic biological tissues. This review provides a comprehensive summary of recent progress in the design, fabrication, and application of OECTs for biological integration. It begins by outlining the fundamental working mechanisms of OECTs and their advantages in transducing biological signals. Key strategies to enhance bio‐tissue interfacing are discussed, including molecular functionalization, interface orientation control, and mechanical matching. The review also covers developments in OECT‐based systems for skin‐mounted and implantable applications, with a focus on maintaining stability and responsiveness under dynamic physiological conditions. Particular attention is given to approaches that improve biocompatibility, reduce foreign body response, and enable minimally invasive operation in vivo. Finally, the article outlines key remaining challenges and suggests future directions to explore in this area.

This article reviews the design, fabrication, and biological application of organic electrochemical transistors (OECTs), emphasizing their potential in tissue‐interfaced bioelectronics. It covers the fundamental principles of OECTs, strategies for enhancing tissue interfacing, and the development of skin‐mounted and implantable systems. Additionally, it highlights challenges related to biocompatibility and offers insights into future research directions.