A weavable and wearable polymer ultrasonic transducer with a large bandwidth

The rise of Internet of Things technologies has promoted the rapid advancement of wearable health monitoring devices. While medical ultrasound technology holds promise for long-term monitoring to detect critical chronic diseases, current commercial ultrasound probes often lack the flexibility, miniaturization, and comfort necessary for medical wearable devices. To address this gap, we propose a weavable and wearable polymer ultrasonic transducer comprising a matching layer, a backing layer, and a piezoelectric layer. This transducer exhibits a bandwidth of 93%, which is six times that of transducers made from piezoelectric ceramics, and could withstand over 10,000 cycles of bending and twisting deformations. The transducer successfully monitors blood flow velocity and measures vessel thickness in the carotid artery and cardiac vessel, achieving a signal-to-noise ratio comparable to that of commercial probes. Its wideband property, with a bandwidth of 3.68–10.08 MHz, allows for the monitoring of various tissues through frequency adjustment. Furthermore, the weavable ultrasonic transducer in fiber form is seamlessly integrated into breathable textiles for real-time cardiovascular monitoring without compromising comfort.