The Polymer Society of Korea

Abstract

Unlike normal skin, wounds often become alkaline, making pH a key biomarker of infection and wound status. However, conventional pH sensors lack mechanical and chemical tolerance for wearable use and require additional circuits due to the absence of on-device memory, reducing long-term reliability while increasing power consumption and device size.
To address this, we suggest an in-memory pH sensor based on an organic electrochemical transistor, in which a semi-interpenetrating polymer network (semi-IPN) is incorporated into both the channel and the pH-sensitive electrode. The semi-IPN structure ensures material tolerance under physical and chemical stimuli. Also, the ethylene oxide moieties in channel network promote ionic transport to achieve high signal amplification, while residual silanol groups subsequently trap the penetrated ions, thereby imparting pH-induced memory characteristics. We believe that our approach can contribute to next-generation wound healing monitoring systems.