Ultrasound-Powered Micro-Robots: Inspired by Starfish Larva

The Emerging Field of Microrobotics

Microrobots have long captured the imagination of researchers and engineers. These innovative technologies promise a wide range of applications, particularly within the healthcare sector.

Potential uses frequently cited include precise medication delivery and the performance of intricate microsurgical procedures.

Addressing the Challenge of Microrobot Mobility

A significant hurdle in the development of these devices is achieving effective mobility. A key question is how to power movement without relying on traditional components like batteries.

While magnetic propulsion is often proposed, a research group at ETH Zurich is investigating an alternative approach utilizing ultrasound.

Biomimicry and the Design of Ultrasound-Driven Microrobots

These microrobots, measuring less than the width of a human hair, were fabricated using photolithography. Their surfaces are coated with synthetic structures mimicking the cilia found on starfish larvae.

In nature, these minute, hair-like projections generate swirling patterns in the water, enabling the young starfish to navigate their environment. This is achieved by either expelling or drawing in surrounding fluid.

Ultrasound Propulsion and Demonstration of Movement

The research team successfully replicated this propulsion mechanism in their tiny robots by applying ultrasound waves. This allows the robots to move in a directed, linear fashion.

The plastic microbeads visible in accompanying visuals were added to the fluid to illustrate the circular flow patterns created around the robot as it moves.

Potential Applications in Targeted Drug Delivery

Drug delivery represents a primary area of application, specifically the ability to administer medication directly to affected areas, such as a stomach tumor.

This targeted approach could maximize therapeutic efficacy while minimizing undesirable side effects.

Future Research and the Importance of Real-Time Imaging

“However, a substantial challenge must be addressed before this becomes a reality: imaging,” according to the university. “Guiding these minuscule machines to their intended destination necessitates the generation of a clear image in real time.”

The researchers are currently working to enhance the visibility of the microrobots by integrating contrast agents commonly used in medical ultrasound imaging.