Flexible large-area ultrasound arrays for medical applications made using embossed polymer structures

Abstract

With the huge progress in micro-electronics and artificial intelligence, the ultrasound probe has become the bottleneck in further adoption of ultrasound beyond the clinical setting (e.g. home and monitoring applications). Today, ultrasound transducers have a small aperture, are bulky, contain lead and are expensive to fabricate. Furthermore, they are rigid, which limits their integration into flexible skin patches. New ways to fabricate flexible ultrasound patches have therefore attracted much attention recently. First prototypes typically use the same lead-containing piezo-electric materials, and are made using micro-assembly of rigid active components on plastic or rubber-like substrates. We present an ultrasound transducer-on-foil technology based on thermal embossing of a piezoelectric polymer. High-quality two-dimensional ultrasound images of a tissue mimicking phantom are obtained. Mechanical flexibility and effective area scalability of the transducer are demonstrated by functional integration into an endoscope probe with a small radius of 3 mm and a large area (91.2×14 mm2) non-invasive blood pressure sensor.

Flexible ultrasound arrays with embossed polymer structures for medical imaging

“…These flexible transducer arrays have found extensive applications in human blood pressure detection [11] , cardiac imaging [12] , blood flow doppler imaging [13] , tissue modulus detection [14] , and tissue deep hemoglobin detection [15] . However, this approach does have some inherent limitations, such as a smaller functionalized drive area, the absence of a transducer backing layer [16] , lower resolution due to reduced integrated density, and potential concerns regarding heavy metal hazards associated with lead, etc.…”