Integrated Ultrasonic Platform for Bioelectronic Control through Biological Barriers Based on Metasurface.

Closed-loop bioelectronic systems that adapt stimulation to real-time physiological feedback hold transformative potential for treating neurological and cardiac disorders and are emerging as key components of future ultrasonic brain-machine interfaces (uBMIs). Realizing this requires the simultaneous achievement of millimeter‑scale deep-tissue targeting, artifact-free physiological feedback, and robust wireless power and data transfer, which remain elusive with current methods. Here, we present an integrated ultrasonic platform engineered to overcome these fundamental limitations. We propose a physics-constrained metasurface design framework to enable high-resolution multifocal ultrasound energy delivery through highly aberrating biological barriers such as the skull and ribs, achieving improved experimental targeting accuracy (e.g., ±6.5% intensity uniformity across multiple foci). We demonstrate the platform's adaptive stimulation capabilities through two distinct paradigms: attention-based ultrasound stimulation and cardiac-synchronized ultrasound stimulation. Furthermore, we introduce a novel dual-channel acoustic link that enables continuous wireless power and wireless data streaming through the skull with a single acoustic metasurface, demonstrating robustness even with a 400-fold power differential. This integrated ultrasonic framework, providing seamless integration of precise spatial targeting through biological barriers, adaptive physiological feedback, and untethered operation, contributes to the development of next-generation uBMIs and closed-loop bioelectronic therapies.