Bioelectronic devices, with their potential to offer high spatiotemporal resolution in biological studies and health monitoring, require precise and stable connections to living tissues. Conformability, stretchability, and strong bonding are prerequisites for successful interfacing, which entails direct contact between the sensing surface and the tissue. This delicate balance has proven elusive, particularly when it comes to semiconductors used in transistor-type bioelectronic devices.

Organic electrochemical transistors (OECTs) based on semiconducting polymers have emerged as a promising avenue for active sensing. These transistors offer built-in signal amplification, low operating voltage, and a natural affinity for ion-based biological events. The key to their success lies in achieving an optimal connection between the semiconducting channel and the tissue surface, a challenge that existing fixation methods and adhesive applications have struggled to meet.

Innovative bioadhesive polymer semiconductor (BASC) film employs a double-network structure that marries a semiconducting polymer with a separate tissue-adhesive polymer. The result is a semiconducting film with remarkable properties: rapid and robust adhesion to wet tissue surfaces, excellent charge-carrier mobility (~1 square centimeter per volt per second), high stretchability, and biocompatibility. This BASC film is a game-changer in the realm of bioelectronics. While previous attempts have explored tissue-adhesive polymers and hydrogels, none have succeeded in creating bioadhesive semiconductor films due to the challenges posed by semiconducting polymers' long side chains and compatibility issues. The BASC film overcomes these obstacles, offering both continuous charge-transport pathways and controlled aqueous swellability—two essential factors for achieving optimal electrical performance.

Bioadhesive polymer semiconductors and transistors for intimate biointerfaces

Nan Li, Yang Li, Zhe Cheng, Youdi Liu, Yahao Dai, Seounghun Kang, Songsong Li, Naisong Shan, Shinya Wai, Aidan Ziaja, Yunfei Wang, Joseph Strzalka, Wei Liu, Cheng Zhang, Xiaodan Gu, Jeffrey A Hubbell, Bozhi Tian, Sihong Wang