Transparent conducting oxides (TCOs) are crucial for high-performance displays, solar cells, and wearable sensors. However, their high process temperatures and brittle nature have hindered their use in flexible electronics. In this paper, we overturn these limitations by harnessing Cabrera-Mott oxidation to fabricate large-area, two-dimensional (2D) transparent electrodes via liquid metal printing. Our robotic, vacuum-free process deposits ultrathin (2–10 nm) indium tin oxide (ITO) with exceptional flexibility, transparency (>95%) and conductivity (>1300 S/cm) by utilizing hypoeutectic In-Sn alloys to print at <140 °C. Detailed characterization reveals the efficacy of Sn-doping and high crystallinity with large, platelike grains. The ultrathin nature enhances bending strain tolerance and scratch resistance, exceeding durability of PEDOT and offering low contact impedance to skin comparable to Ag/AgCl. We implement 2D ITO in synchronous, multimodal electrocardiography (ECG) and pulse plethysmography (PPG) measurements. This order-of-magnitude improvement to printed TCOs could enable wearable biometrics and display-integrated sensors.

透明导电氧化物 （TCO） 对于高性能显示器、太阳能电池和可穿戴传感器至关重要。然而，它们的高过程温度和脆性阻碍了它们在柔性电子产品中的应用。在本文中，我们通过利用 Cabrera-Mott 氧化通过液态金属打印制造大面积二维 （2D） 透明电极来克服这些限制。我们的机器人、无真空工艺通过利用亚共晶 In-Sn 合金在 <140 °C 下打印，沉积超薄 （2–10 nm） 氧化铟锡 （ITO），具有卓越的柔韧性、透明度 （>95%） 和导电性 （>1300 S/cm）。 详细的表征揭示了 Sn 掺杂和高结晶度对大板状晶粒的功效。超薄特性增强了弯曲应变容限和耐刮擦性，超过了 PEDOT 的耐用性，并且对皮肤的接触阻抗可与 Ag/AgCl 相媲美。我们在同步、多模态心电图 （ECG） 和脉搏体积描记法 （PPG） 测量中实施 2D ITO。对印刷 TCO 的这种数量级改进可以实现可穿戴生物识别和显示器集成传感器。