Tissue-like organic electrochemical transistors

Organic bioelectronics has gone wild over the past few decades. As flagship devices, organic electrochemical transistors (OECTs) provide a new choice for next-generation bioelectronic devices because of their excellent water stability and ability to convert small ionic signals to stronger electronic signals (iontronic amplifiers) at extremely low voltage. However, device failure occurs when OECTs are introduced at tissue-electronic interfaces due to the mechanical mismatch between the stretchable tissues and the non-stretchable devices. Tissue-like OECTs aim to make a paradigm shift to unlock the potential of OECTs for applications at soft bioelectronic interfaces by acquiring the mechanical stretchable and healable properties of soft tissues. The stretchability allows OECTs to conform better with soft tissues under motion or deformation, while the self-healing ability permits fast recovery of the electronic functionality after accidental damage. In this article, we highlight the recent trends in developing tissue-like OECTs. Challenges in materials, devices, fabrications, and applications are summarized. Finally, we present our view on how tissue-like OECTs can serve as a new building block to impact exciting new areas, including wearables and implantable medical devices, e-skin, soft robotics, and soft neuroelectronics.