A opto-thermal micro-transportation for cellular microbiology

Abstract

Cellular microbiology requires a tool that can efficiently transport biological micro-objects, including single cells, cell clusters, microbeads and microscale hydrogels (microgels) laden with cells or chemicals. The transportation of these micro-objects is useful in many areas such as single-cell research and the construction of in vitro artificial tissue. In this dissertation, opto-thermocapillary flow-addressed bubbles (OFB) are evaluated for transporting biological micro-objects. Control over the OFB was accomplished by developing an engineered free-space optical addressing system. The OFB provides a new micro-transportation tool for cellular microbiology. It complements other cell-manipulation technologies such as optical tweezers and dielectrophoresis (DEP), as it is less dependent upon the optical and electrical properties of the working environment, enabling functionality in cell culture media. OFB also distinguishes itself by the capability for on-demand creation of micro-transporters, eliminating the need for microfabricated micro-transporters that need to be introduced into the working space. Further, the straightforward actuation mechanism of OFB enables parallel and cooperative micro-transportation using commercial beam-forming devices. OFBs with varying dimensions were used to transport biological micro-objects such as microbeads, single cells, and cell-laden microgels. The micro-objects were patterned into different geometries to show the potential applications for engineering artificial tissue. The results of each transportation was subjected to viability tests or subsequent cell culturing to check the effects on the biological micro-objects. High cell viability rates were observed, showing OFB is a dexterous and reliable biological micro-transportation tool.