Micropatterned Biphasic Printed Electrodes for High‐Fidelity on‐Skin Bioelectronics

Abstract Skin‐interfacing electrodes are central to health monitoring, rehabilitation, stimulation, gaming, and AR/VR. Next‐generation wearables demand high signal quality, conformability, and long‐term comfort, yet existing gel and dry electrodes fall short. It is presented microprinted biphasic soft electrodes whose 3D microstructure and embedded liquid‐metal droplets enlarge true skin contact and reduce contact impedance to 4.7 kΩ—a 14.1‐fold reduction relative to Ag/AgCl (66.1 kΩ). The electrodes enable forehead EEG detection of the Berger effect, previously impractical with conventional electrodes, and deliver robust SNR during prolonged wear and motion. A simple model links infill geometry to effective surface area, guiding optimization and validated in n = 10 subjects. These versatile electrodes enable high‐fidelity monitoring of muscle, heart, and brain signals for healthcare and advanced human‐machine interfaces (HMIs), establishing a transformative paradigm for wearable bioelectronics in healthcare, neuroprosthetics, and advanced HMIs.