| Silicon microfabrication technology has enabled the creation of microfluidic devices for performing complex manipulation of fluid samples on enclosed microchips. Researchers hope to use this platform to create miniaturized, portable systems based on many biological, chemical, and medical analyses currently performed in wet labs; these devices have applications in an almost limitless number of fields, from medical diagnostics to water treatment to detection of explosives. But truly useful microfluidic devices require more than just fluidic channels; they require chemical, biomolecular and/or electronic components as well. And while each these components can be created alone, fundamental incompatibilities in fabrication processes---polymer microfluidic channels cannot withstand solvents used in IC processing, and biomolecules such as proteins and DNA denature when exposed to high temperatures required for microchannel fabrication---have prohibited their integration into complete, functional devices.;This thesis describes a solution to these fabrication incompatibilities through intelligent assembly of functionalized substrates. Biological, electronic and fluidic components are created as individual components and then assembled to form a complete, integrated microfluidic device. Precision during the assembly step is vital, as misalignment between components will negatively impact the device's overall accuracy; until now no method was available that could produce less than 15 microm alignment error. The kinematic alignment system developed in this research provides a high precision, optics-free technique for making integrated microfluidic devices. The system uses traditional precision machine design components---a kinematic coupling with integrated linear flexural bearing---to provide passive alignment with up to 1-2 microm precision. The result is a low-cost system flexible enough to handle a wide variety of biochemical and physical components, and is scalable to multiplexed assembly. |
