Micro-led based optoelectronic tweezers

• Main Author: Jeorrett, Abigail Helen
• Published: University of Strathclyde 2015
• Subjects: 610.28
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.668887

Micromanipulation tools are a valuable component of biomedical research. A fundamental example is in the study of the complex pathways involved in disease progression in which controlling immune cell interactions at a single-cell level is crucial to the discovery of new treatments. Current cell manipulation tools employ a wide range of mechanisms however, future systems must be geared towards miniaturisation to provide portable and convenient systems which are simple and cost effective for use in research. In this thesis, the use of micro-LEDs as a compact illumination source in optoelectronic tweezers systems is explored. The emerging technique of optoelectronic tweezers uses light patterns to generate electric field gradients to trap and manipulate single cells. Micro-LEDs offer an advantageous alternative to current illumination sources used in this technique, and indeed other light-based micro-systems, in terms of a compact design and control system, low cost and the potential for integration with other micro-systems. Initially, single-cell trapping and fluorescence imaging of immune cells is demonstrated using a micro-LED projection system in which the size of the imaged pixel array was reduced to better match the scale of cells. Using this system, individual cells were trapped and the velocity profile at varying applied voltages and the trap profile were measured. Fluorescently labelled cells were identified in a mixed population through micro-LED excitation and a common indicator of cell activation (calcium fluxing) was also monitored over time showing the combined capabilities of this system. The creation of a novel, integrated micro-LED/OET device for the manipulation of live cells in a compact format is then reported. In this system, the direct integration of a micro-LED array with an optoelectronic tweezers chamber was achieved where cells were successfully manipulated. In addition, interesting combined field effects were observed and potential future developmental prospects were identified.