Overview
- Researchers at ETH Zurich embedded ~100‑micrometer microbubbles in patterned silicone membranes, which oscillate under ultrasound to generate flows that deform the material.
- By tuning bubble sizes and ultrasound frequency or amplitude, the actuators switch between uniform bending and undulatory waves for programmable motion patterns.
- Proof-of-concept devices included a stingray-like swimmer driven wirelessly and a soft gripper that captured and released a live zebrafish larva without observed harm in lab tests.
- A wheel-like structure navigated convolutions of an ex vivo porcine intestine by selectively stimulating differently sized microbubbles to steer.
- The team highlights prospects such as targeted drug delivery, minimally invasive tools and tissue patches, while noting the platform remains preclinical and requires in vivo validation and robustness improvements.