The objective of this research is to investigate a novel class of optical tweezers which can trap and manipulate liquid droplets with large force. The approach, termed optofluidic tweezers (OFT), is based on the photomechanical conversion of light into 3-dimensionally confined thermocapillary microvortices which align a droplet on the axis of a focused laser.
Intellectual Merit. OFT relies on capillary forces, a mechanism fundamentally different from traditional optical tweezers. It can attain forces in the ÂµN range, which is 100,000X larger than optical tweezers and 1,000X larger than optoelectronic tweezers. This unique feature makes OFT a potentially transformative approach for liquid manipulation over a wide range of length scales. This research will build a fundamental understanding of the energy transduction and trapping mechanism through the systematic study of flow fields, temperature profiles, holding forces, geometric scaling, and material properties. It will also create a prototype system for OFT-based manipulation.
Broader Impacts. Optical manipulation tools are broadly used in biology, physics, and engineering, typically at the micro and nanoscale. Due to its large force, OFT can extend these capabilities to the millimeter scale, enabling new applications in electronics manufacturing and lab-on-a-chip systems. This highly interdisciplinary project combines optics, fluid dynamics, and interfacial phenomena, providing a unique platform for training graduate and undergraduate students. The PI will leverage Wayne State University?s established channels for recruiting underrepresented minorities. The PI will also develop a ?jello microfluidics? module for Detroit Science Center Nanodays, an NSF-sponsored program for nanoscale science education targeted to K-12 students.