Understanding Swelling Mechanisms for Controlling the Mechanical Properties of Channels in OECTs

Organic electrochemical transistors (OECTs) are promising platforms for biosignal recording and bioelectronic applications owing to their efficient ion-electron coupling, high signal amplification, and stable operation in aqueous environments. However, OMIEC channel materials possess intrinsic mechanical properties that are difficult to adapt to diverse application environments. In particular, mechanical mismatch between the OMIEC channel and biological tissue can induce stress accumulation, leading to physical degradation of the channel and reduced device performance. Therefore, understanding the mechanisms of swelling is essential for controlling the mechanical properties of OMIEC channels and improving the compatibility of OECTs. In this study, we investigate swelling phenomena in various OMIEC materials and identify key parameters that modulate swelling behavior, thereby enabling control over their mechanical properties during OECT operation.