Silicon nanocolumn-based disposable and flexible ultrasound patches
Dong-Hyun Kang, Seonghun Cho, Hae Youn Kim, Shinyong Shim, Dong Hun Kim, Baren Jeong, Yoon Seong Lee, Eun‐Ah Park, Whal Lee, Hyungmin Kim, B.T. Khuri-Yakub, Maesoon Im, Jae‐Woong Jeong, Byung Chul Lee
Abstract
Traditional wearable ultrasound devices pose challenges concerning the rigidity and environmental impact of lead-based piezoelectric materials. This study proposes a silicon nanocolumn capacitive micromachined ultrasonic transducer (snCMUT) array for real-time wearable ultrasound imaging in disposable patches. Using a lead-free design, snCMUT incorporates silicon nanocolumns to address existing issues and achieves high transmission efficiency (220 kPa/V), flexibility, and low power consumption. The specialized structure of snCMUT enhances displacement efficiency, enabling high-resolution imaging while maintaining a thin, flexible form factor (~900 μm). Phantom imaging demonstrates its superior performance, with high axial and lateral resolutions (0.52 and 0.55 mm) and depth penetration (~70 mm) at low voltage (8.9 VPP). Upon successful application to monitor both sides of the human carotid arteries, snCMUT offers clear ultrasound images and continuous blood pressure waveform monitoring. This proposed innovation presents significant potential for continuous medical imaging and cardiovascular health assessment, addressing environmental concerns and reducing manufacturing costs (<$20). A lead-free, flexible, and disposable ultrasound patch using silicon nanocolumns enables vascular imaging and real-time blood pressure monitoring, offering a low-cost and eco-friendly solution for wearable medical diagnostics.