Ultrasound-sensitive microrobotic sensor with robust anchoring for long-term digestive lesion assessment

Microrobots have achieved notable progress in targeted drug delivery for treating various diseases. However, employing the microrobot itself as a microsensor for remote and long-term lesion assessment remains challenging. Here, we design a bioinspired ultrasound-sensitive microrobotic sensor (USMS) capable of robust anchoring for wireless and long-term digestive disease treatment and assessment. The USMS integrates dual magnetic and focused ultrasound actuation for precise locomotion and on-demand drug delivery, while a bioinspired microneedle design secures stable anchoring against strong fluid flow (402 mm/s) and peristaltic forces (66.5 mN). More importantly, the air cavity design of USMS enables strong ultrasound reflection for remote and long-term sensing of protruding lesion radius to assess therapeutic efficacy. Overall, USMS demonstrates reliable on-demand drug delivery and lesion size sensing capabilities in mouse models. The USMS has the potential to serve as a versatile robotic platform and sensing system for monitoring lesion evolution in clinical disease management.