Optothermal Analyte Manipulation With Temperature Gradient Focusing

An optothermal analyte preconcentration method is introduced in this work based on temperature gradient focusing. The present approach offers a flexible, noncontact technique for focusing and transporting of analytes. Here, we use a commercial video projector and an optical system to generate heat and control the heat source position, size and power. This heater is used to focus a sample model analyte, fluorescent dye, at an arbitrary location along the microchannel. Optothermal manipulation of the focused band was demonstrated by projecting a series of images with a moving light band.