Biodegradable ultrasound contrast tape for tracing intestinal motility

Postoperative complications such as intestinal motility disorders and obstructions require regular monitoring following small intestine resection. While imaging techniques like MRI and CT offer high-resolution visualization of internal organs, their use is limited by the need for trained operators and constraints on frequent monitoring. Ultrasonography, although capable of continuous imaging of deep tissues, is challenged by the weak acoustic reflections from soft intestinal tissue. In this work, we present a biodegradable ultrasound contrast tape (BioUCT) designed for robust, conformal adhesion to the intestinal surface to enable high-contrast ultrasound imaging. The soft BioUCT has a strong ultrasound reflection (>90%), generated from periodic air cells sealed in tough hydrogels. The BioUCT achieved ultrasound contrast imaging of the small intestine for 2 weeks and degraded naturally within 12 weeks in a live pig, enabling the regular and wireless monitoring of postoperative intestinal motility.