Glass-based lab-on-a-chip devices fabricated by femtosecond laser processing

Lab-on-a-chip devices that miniaturize all functionalities of biological and chemical laboratory into a single substrate have a tremendous potential to improve the life science research. Femtosecond laser can provide relatively easy, fast, and convenient glass processing method, leading to glass-based lab-on-a-chip device fabrication. This work aims to enhance understanding on the nature of high-repetition-rate femtosecond laser interaction with glass material in terms of the heat accumulation effect. It also aims to develop a glass-based lab-on-a-chip device for detecting and counting single cells using femtosecond laser processing.;First, normal reflection variation of focal volume is presented as an indicator representing accumulated temperature during high-repetition-rate femtosecond laser irradiation. Infrared (3--5microm) thermal emission that matches predictions of transient thermal utilizing Planck's blackbody radiation distribution explains thermal behavior of focal volume.;An in-situ femtosecond laser processing and characterization setup is developed for studying surface damage effect on longitudinal waveguide performance. The proposed setup and processing window enables enhancement of single-step longitudinal waveguide integration with microfluidic channel and fabrication of 3D optofluidic circuit structures.;With respect to the latter, integration of three-dimensional microchannel and optical waveguide structures inside fused silica is demonstrated for the interrogation and processing of single cells. The microchannels are fabricated by scanning femtosecond laser pulses and subsequent selective wet etching process. Optical waveguides are additionally integrated with the fabricated microchannels. Single red blood cells (RBC) in diluted human blood inside of the manufactured microchannel were detected by two optical schemes.;Femtosecond laser processing is proposed to fabricate three dimensional optical waveguide and microfluidic channel in glass material. The optical cell detection experiments support potential implementation of a new generation of glass-based lab-on-a-chip devices in various single cell treatment processes including laser based cell processing and sensing.