Our project explores the design and function of acoustically driven microrobots using two distinct acoustic fields: planar waves [A-C] and focused ultrasound [D,E]. We have developed a variety of microrobots with unique shapes and sizes, fabricated through advanced techniques like two-photon polymerization [A-C] and chemical synthesis [D,E]. This approach allows us to test different acoustic propulsion mechanisms and investigate how these can be modulated to enhance performance.
Through this process, we achieved microrobots capable of different locomotion modes, depending on the acoustic input parameters presented to the microrobots [A]. Additionally, we identified a novel geometry for acoustic trapping—hierarchical superstructure particles [E]—that can be held in place by focused ultrasound even under high flow conditions. This breakthrough has enabled us to extend the technology to in-vivo applications, opening new avenues for biomedical use.
To gain deeper insight into the underlying physics, we integrate finite element simulations [B] with experimental validation, allowing us to fine-tune these geometries for optimal locomotion and stability. Beyond propulsion, we are exploring additional functionalities such as acoustic streaming, which enables the microrobots to carry and transport cargo, broadening their potential for targeted delivery and medical interventions.
Our work combines theoretical and experimental approaches to not only optimize propulsion but also expand the functional capabilities of microrobots, setting the stage for next-generation applications in biomedical engineering and beyond.