Dynamic manipulation by light and electric fields: micrometer particles to microliter droplets.
We demonstrate a new hybrid optoelectric technique that can manipulate objects across several length scales. The technique leverages a variety of different physical mechanisms to achieve the dynamic manipulation of droplets and also the in situ concentration of colloidal particles suspended in the droplets. Various physical mechanisms such as optoelectrowetting, electrothermal flows, and ac electroosmosis are leveraged through different modes of operation of the device. Each operational mode, which is activated through the proper combination of an applied ac bias and the illumination used, is characterized by the ability to manipulate objects on a certain length scale. We also demonstrate that the device lends itself to the active control of microstructure patterns that emerge from a droplet evaporation process.
Kumar
Aloke
A
Birck Nanotechnology Center and School of Mechanical Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
Chuang
Han-Sheng
HS
Wereley
Steven T
ST
D003102:Colloids; D004560:Electricity; D008027:Light; D010316:Particle Size
D003102:Colloids