Flexible skull-conformal phased array for aberration-corrected transcranial focused ultrasound therapy

Transcranial focused ultrasound (tFUS) is a promising non-invasive tool for precise deep-brain interventions, including neuromodulation, blood-brain barrier opening, and drug delivery. However, achieving reliable acoustic coupling and accurate phase correction remains challenging due to skull curvature variability and skull-induced aberrations. To address these challenges, we present the first flexible, skull-conformal aberration-corrected phased array (F-SCAPA), a transformative solution integrating mechanical adaptability with advanced acoustic correction. The 0.5-MHz array-comprising 8 × 8 elements-features an optimized fabrication process that enhances material efficiency, ensures flexibility and stretchability, and maintains uniform electrical performance. Coupled with CT-based skull modeling and time-reversal aberration correction, F-SCAPA dynamically conforms to cranial anatomy while compensating for phase distortions. Transcranial validation in a human skull demonstrates precise focusing at 36 mm depth, achieving an axial full width at half maximum (FWHM) of 8.9 mm. This breakthrough overcomes existing limitations by combining mechanical adaptability with high-resolution transcranial focusing, establishing F-SCAPA as an advanced system-level pathway toward more adaptable transcranial ultrasound devices for research and low-intensity therapeutic applications.