Light-Driven Microdrones

Optical tweezers have revolutionized biological physics and related research. Thanks to them, scientists are able to precisely study and manipulate individual minuscule objects like biological cells and their internal components. Yet, even this remarkable tool has its limitations. For example, it is hard to change the orientation of a trapped object and thus to access it from several sides, or to make several small objects interact in a targeted manner. As an additional challenge, operating the optical tweezers requires a high level of understanding of their underlying physics.

Scientists from the University of Würzburg have developed an entirely new approach to micromanipulation and -assembly, based on a set of microdrones. Powered simply and yet precisely by unfocused light, the drones move freely in solution – forward, backward, sideways and by rotating around their own axis, just like their macroscopic quadcopter cousins do in the air.

Ongoing research aims at equipping the microdrones with functional tools, enabling them to lock a cell or other small object in place under a microscope, as well as to rotate it for improved access from all sides. Microbiological and nanoscale payloads could then be captured, transported and delivered to build tailored nanostructures. Cells could be treated from angles not easily accessed by classical micropipettes, e.g. by bringing in a metal particle via microdrone and heating it with a laser. Fitting a microdrone with a probing tip could enable it to scan and analyze a liquid-solid interface.

• Applicable in a wide and diverse range of laboratory settings
• Easy steering with little specialist knowledge
• More versatile than current optical tweezers and micromanipulators
• Highly flexible tool aimed at a growing market for nanotools

Real microdrones move accurately as intended in the lab. (See link below.) Experiments with functional payloads are currently ongoing.