Micro-Fabrication of All Silicon 3 Meter GC Columns Using Gold Eutectic Fusion Bonding

Abstract

This work highlights a new bonding technique for micro-fabrication of an all silicon 3 meter gas chromatography column that could withstand the temperature cycling required for axial temperature programming. Proper separation of a complex gas mixture using a miniaturized GC column is critical in improving the overall performance of a lab on a chip system for environmental monitoring, medical diagnoses, and gas impurity measurement. To improve upon current methodology the column was first fabricated using micro-fabrication processes; experimentally validated using a high performance 3 meter GC column coated with OV-1 stationary phase. This process demonstrates that the bonding quality of the GC column to a 200 μm thick silicon lid was improved when using a new gold eutectic bonding technique. Furthermore, a new quality control technique was developed in order to test the overall bonding quality of the bonded pieces by fixing the bottom column and applying a mechanical shear force to the top lid. This method could ultimately be used for quality control of each individual bonded columns. The gold bonded interface of the gold diffusion bonded area is further characterized using surface analysis. In the end, the utility of the column was demonstrated by separating 21 organic compounds with different Kovats retention index and molecular weights in less than five minutes.

Transient thermal response of micro-thermal conductivity detector (µTCD) for the identification of gas mixtures: An ultra-fast and low power method

“…The lower power required in this method of operating this µTCD measurement system allows its integration into ultra-portable or wearable sensing devices. In addition, evolving miniature gas analyzer technologies such as micro-GC systems 17,18 demand the integration of highly efficient and fast micro-detectors, which could be another potential application for this technology.…”

All Silicon Micro-GC Column Temperature Programming Using Axial Heating

“…The process for fabrication an all-silicon GC columns was described in our previous work [17,18]. To investigate the axial temperature gradient, three heater designs were investigated.…”

High density semipacked separation columns with optimized atomic layer deposited phases

“…This stationary phase deposition technique has been successfully employed by our group for a monolithically integrated separation and detection module [24] and a single chip GC system (injection, separation, and detection) [26]. A consistent research effort is also being made to use new fabrication techniques [27,28], novel substrate and coating materials [29][30][31][32], on-chip fluidic interconnects [33], system level component integration [31,[34][35][36][37][38][39], and application-specific stationary phases [40,41] to further enhance the capabilities of micro gas chromatography (µGC) system.…”