Design and micromachining of a stretchable two-dimensional ultrasonic array

Abstract

Focused ultrasound using stretchable ultrasonic arrays is a very attractive method for ultrasound neuromodulation. However, the structure and fabrication of the arrays have brought great challenges for the development of stretchable ultrasonic arrays. In this work, an improved 6 × 6 stretchable two-dimensional ultrasonic array has been proposed based on laser micromachining technology. The structure and shape of the serpentine hinge are optimized to avoid delamination between layers and to reduce the stress concentration during the stretching process. Due to the thorough studies over the effects of laser parameters on the kerf profile, clean and accurate serpentine hinge shapes can be obtained conveniently. Array elements are connected using serpentine hinges to form a stretchable two-dimensional structure. Thus, a reliable electrical connection and stable array structure are formed, which can provide 100% yield and excellent mechanical stretchability. Based on the three-dimensional scanning guidance, simulation results of ultrasonic spatial focusing on a complex surface demonstrate that our device has promising applications for ultrasound neuromodulation. • An improved 6 × 6 stretchable two-dimensional ultrasonic array with row and column electrodes. • Optimized serpentine hinge reducing the maximum stress during array stretching. • Laser micromachining serpentine hinge with clean and accurate profile. • Spatial focusing of the stretchable ultrasonic array based on three-dimensional fast scanning.