Printing flexible two-dimensional indium tin oxide for multifunctional transparent bioelectrodes
摘要
Transparent conductive oxides (TCOs) are a high-performance material system that could enable new wearable sensors and electronics, but traditional fabrication methods face scalability and performance challenges. In this work, we utilize liquid metal printing to produce ultrathin two-dimensional (2D) indium tin oxide (ITO) films with superior microstructural, optical, and electrical properties compared to conventional techniques. We investigate the dynamics of grain growth and its influence on conductivity and the optical properties of 2D ITO, demonstrating the tunability through annealing and multilayer deposition. Additionally, we develop Au-decorated transparent electrodes, showcasing their adhesion and flexibility, low contact impedance, and biocompatibility. Leveraging the transparency of these electrodes, we enable enhanced simultaneous multimodal biosignal acquisition by integrating biopotential-based methods, such as electrocardiogram (ECG) or bioimpedance sensing (e.g., impedance plethysmography, IPG), with optical modalities like photoplethysmography (PPG). This study establishes CLMP-fabricated flexible 2D TCOs as a versatile platform for advanced bioelectronic systems and multimodal diagnostics.
Graphical abstract