Liquid handling has always required the use of containers, but a recent development in ultrasound technology has opened up new possibilities. Scientists at the University of Tsukuba have created a “lab-on-a-drop” environment, where liquid droplets can float and mix in space without the need for a container. This breakthrough has the potential to revolutionize various fields of science and technology.
In this lab-on-a-drop setup, two microscopic droplets need to be merged, which is challenging due to their small size. The researchers at the University of Tsukuba have successfully developed a technique for merging two droplets using an ultrasonic phased array. By creating a focal point with the ultrasonic waves, the droplets can float randomly and collide, leading to merging.
Measuring Fluid Mixing
To understand and analyze the process of fluid mixing within the merged droplets, the researchers utilized a novel measurement technique. They introduced red and green fluorescent emitting particles into each droplet. When exposed to ultraviolet light, the particles fluoresce, allowing their motion to be captured by a high-speed camera.
By analyzing the images captured by the camera, the researchers were able to visualize the fluid flow and distribution within the droplets. This groundbreaking technique unveiled the internal flow caused by surface vibration during the merging process. The estimation of fluid motion within each droplet provides valuable insight into the mixing dynamics.
Predominance of Interfacial Vibration
The comparative analysis of the difference between fluid mixing due to interfacial vibration and molecular diffusion revealed an interesting finding. The mixing caused by interfacial vibration was found to be predominant and had a significant impact on the overall fluid mixing process. This understanding opens up avenues for further research and application of lab-on-a-drop devices.
Implications of the Research
The research conducted by the University of Tsukuba holds great promise for the future of lab-on-a-drop technology. The ability to visualize and understand fluid flow within levitated droplets can lead to significant advancements in various scientific and technological fields. This breakthrough could enable the development of more efficient chemical reactions, improved drug delivery systems, and enhanced microfluidic devices.
The development of a technique for visualizing fluid flow in levitated droplets using fluorescence-emitting particles is a remarkable achievement. By merging microscopic droplets and analyzing the internal flow, researchers have gained valuable insights into the mixing dynamics. This research paves the way for the future development and application of lab-on-a-drop devices, with the potential to revolutionize various industries.