The first project, supported by a $335,000 grant through the NSF's Electronics, Photonics and Magnetic Devices program, will investigate what Basu calls a novel approach for controlling the motion of droplets using lasers. Titled "Optofluidic Tweezers" (OFT), the project focuses on a technique that can generate forces 100,000 times larger than traditional optical tweezers. The technology, recently patented by Wayne State's Technology Commercialization Office, enables novel applications in microscale liquid control, particle manipulation and light-directed assembly.
OFT uses Marangoni flow, a surface tension-driven phenomenon that becomes more powerful at a small scale.
Basu uses the Marangoni effect to grab a droplet on the axis of a focused laser, resulting in a class of optical tweezers that can trap and manipulate liquid droplets with large force. By scanning the laser in two dimensions, he can move droplets as needed for liquid handling.
The second project, "Tensiophoresis: Label Free Droplet Sorting in Surfactant Microgradients," funded by a $301,000 grant, is jointly supported by NSF programs in Particulate and Multiphase Processes and Chemical and Biological Separations.
A key operation in droplet assays is the ability to detect chemicals in droplets. Tensiophoresis uses the phenomenon of capillary migration to sort droplets based on their chemical composition, without the fluorescent labels typically required in such assays.
In tensiophoresis, a droplet is placed in a small channel between two liquid streams with different interfacial tensions (IFT). Capillary migration causes the droplet to swim into one of the two streams, enabling researchers to sense and sort proteins within droplets for proteomic applications.
"The ability to sort droplets by their IFT is particularly i
|Contact: Julie O'Connor|
Wayne State University - Office of the Vice President for Research