[Micro machining of micro-cantilever probes for efficient deposition for biochips]

Biochip technology will bring a tremendous revolution to life science and medical research in 21 century. Microarray assays represent an essential technical advance in biomedical research. Recently, the demand for microarray assay technology has spring up. Therefore, low cost and flexible techniques are needed to meet specific requirements for increasingly integrated biochips. Also performance must be improved in terms of speed and sensitivity. To this end, promising approaches, mainly based on micro and nanotechnologies, have been developed. In this paper, the design and microfabrication of a novel type of micro-cantilever probe are introduced. These probes were fabricated using silicon dioxide by Micro-electromechanical System (MEMS) techniques, and they featured one micron split gap, microchannels and self-replenishing reservoirs. All fabricated micro-cantilever probe were tested on Nanoarrayer instrumentation. Cy3-streptavidin was loaded as biological sample and patterned on DSU gold surface. Results showed these probes were capable of generating high quality biological arrays with routine spot sizes of 2 - 3 microns and could deposit at least three thousand spots without reloading. The spot size could potentially achieve sub-micron when probe size was further shrunk down by the high-resolution lithography technique or more precise microfabrication technologies, such as E-beam lithography. To further improve sample loading efficiency, it is needed to modify the cantilever surface in order to better confine sample inside the microchannel and reservoir, which will be researched in the future.