Automatized Surface Functionalization for Diagnostic System
Engineering
EE129
Microfluidics has enabled the development of a cost effective, miniaturized, and fast diagnosis tool used to detect and diagnose a patient’s condition by using body fluids (e.g. blood, saliva, sweat, urine). Research into these systems are being performed by Dr. Yanik and his team of researchers Xiangchao (Jude) Zhu and Yixiang Li in the UCSC’s Nano Engineering Group. They envision developing a point-of-care (POC) diagnostic system, a complete solution that can help detect, diagnose, and monitor major diseases like Coronary Artery Disease and Atheroma, while remaining accessible both in cost and approachability. Inspired by their research we are currently bringing their cutting-edge research and their noble goals to fruition. Our team’s goal is to first miniaturize and automate the surface functionalization process of the microfluidic chip for selectively cell capture and to second develop a portable, low power consumption, user interface friendly frequency synthesizer to generate radiofrequency signals with wide frequency and voltage ranges and a tunable phase offset. By integrating these two developed platforms together, a portable, stand-alone, acoustomicrofluidic system can be constructed for the ultimate goal of diagnosis of cardiovascular disease.
Current diagnostic systems require trained personnel, expensive equipment, and a large area, making them infeasible. Our project solves the automation and miniaturization problems of functionalizing a microfluidic chip by providing a unified platform capable of functionalization and surface acoustic wave (SAW) particle separation. The platform is capable of completely autonomous operation and requires very little training to operate attributed by its user friendly interface.
The project is defined through two components: the fluid pumping system and frequency synthesizer. The fluidic pumping system allows for both biologically and chemically functionalizing surface of microfluidic chip through pumping different solutions and washing buffers in a sequential manner. The fluidic system is capable of a well-controlled, minimal pulsating, and air bubble-free output to successfully coat the microfluidic chip with target ligands. The frequency synthesizer is able to generate radiofrequency signals that can be later converted into mechanical signals-SAW through piezoelectric effect. The SAW can be utilized to spatially manipulate the bioparticles such as white blood cells (WBCs) and cancer cells and sort out the undesirable cells to purify the cell sample solution based on the particle volume dependent acoustic radiation force (ARF).
Key features of the autonomous pumping system include: flow-rates ranging from 1-1000[ul/min] with no pulsations, control of 5 valves or even more potentially, 2 syringe pumps, 5 fluid solution selections, and easy wireless control with either an Android app or a desktop client.
Additionally, for the generation of surface acoustic wave (SAW), we developed a portable harmonic frequency synthesizer with a working frequency range of 1-100[MHz]; a tuning resolution of 1[Hz], low harmonic distortion, -60dBc; low noise output, -30 dB; a working voltage range of 60[V]; and phase tenability ranging from 0-180 degrees.
