This award is for developing a new instrument, named "opto-plasmonic tweezers," for optical manipulation of biological cells with fine orientation control and low optical-intensity requirement. Non-invasive manipulation of biological cells with light is an important tool for basic biological research. Opto-plasmonic tweezers use polarized light to excite localized surface-plasmon resonance, which consists of a collection of oscillating electrical dipoles, on a metal nanoparticle array. The orientation of these dipoles is parallel to the polarization direction of the light. They generate a patterned-radiation electric field that manipulates the cells through dielectrophoretic interactions, with orientation control dependent on the polarization of the light. Low optical intensity can be achieved due to the high gradient of the radiation field. A micromachined polarization controller will also be fabricated as the first step towards micro-instrumentation. The micro-polarization controller is expected to achieve sub-millisecond response time and therefore can achieve fast rotation control of the biological cells.
This is a new instrument for manipulating single biological cells non-invasively using light. Such capability is important in biological research and applications. A chief virtue of the technology is its ability to rotate the cells with high resolution by changing the polarization direction of the light, which cannot be achieved by most of the optical manipulation approaches. Such capability opens the door to building structured biomaterials for potential applications in constructing biofilms and human tissue engineering. This instrument will also be miniaturized using micromachining technology so that it will have a small footprint and low cost. The success of this project will open up new directions for optical manipulations in biological research. This project will also give students valuable experience in doing interdisciplinary research.
