ii AbstractWe have designed and fabricated a biomicroviscometer platform for measurement of microflows of biological fluids. The biomicroviscometer combines an optically clear biocompatible polydimethylsiloxane (PDMS) channel with on-chip integrated microfluidic differential pressure sensors and capabilities of modular channel geometries. This setup allows for a direct measurement of the change in pressure and flow rate, increasing the overall accuracy of the measurement of viscosity and optical observation. We present an introduction of this combined method of measurement with different channel dimensions, using Newtonian and non-Newtonian fluids, and the corresponding calculations. This measurement technique has potential applications in measuring rheological properties at the micro level to further blood disease analysis, and lab-on-a-chip fabrication and analysis.Acknowledgements iii