SBIR Phase II: Microfabricated Silicon Devices for Low Cost Microarray

这个小企业创新研究（SBIR）二期项目建议开发一种新的、商业上可行的微机械硅技术平台，用于DNA微阵列的打印，在成本和质量上都比目前的钢钉技术有显著的优势。第一阶段的工作非常清楚地表明，硅针可以可靠地吸收DNA打印溶液，并比商业钢印刷针更好地沉积大小变化的斑点。第二阶段的工作将侧重于开发一种基于干湿蚀刻相结合的新型微加工方案，该方案将允许在所有三个维度上雕刻打印尖端。反过来，这将允许尖端的大小，形状和流体输送特性被微调。打印尖端尺寸（范围：125微米x 125微米到25微米x 25微米）和摄取体积（范围：0到100nL）将允许引脚精确地吸收和提供所需的任何体积或斑点尺寸/形状。再加上新设计的全硅支架中更密集的引脚包装，这些特性将使DNA微阵列以以前无法实现的成本、速度和质量制造出来。该项目的商业应用是在DNA微阵列领域。由于目前用于打印DNA微阵列的手工加工钢钉的弱点（例如极高的制造成本和低产量，针对针的均匀性差，沉积的斑点尺寸范围有限，在吸收和传递死体积中浪费宝贵的DNA，以及由于尖端快速磨损而导致的沉积随时间变化），迫切需要改进打印技术。本项目开发的新型微机械硅打印产品将在很大程度上消除这些缺点，并将凭借其更低的成本、更高的精度和速度，作为现有产品的替代品进入市场。

This Small Business Innovation Research (SBIR) Phase II project proposes to develop a new, commercially viable micromachined silicon technology platform for the printing of DNA microarrays that offer significant advantages over current steel pin technology in cost and in quality. The Phase I effort demonstrated very clearly that a silicon pin reliably imbibed DNA printing solution and deposited spots with a size variance better than that of commercial steel printing pins. Phase II work will focus on the development of a new micromachining protocol based on a combination of wet and dry etching that will allow sculpting of the print tip in all three dimensions. This, in turn, will permit the size, shape and fluid delivery characteristics of the tip to be finely tuned. Printing tip sizes (range : 125 microns x 125 microns to 25 microns x 25 microns) and uptake volumes (range : 0 to 100nL) will allow the pins to precisely take up and deliver any volume or spot size/shape desired. Combined with a much denser packing of pins into a newly designed, all-silicon holder, these attributes will allow DNA microarrays to be fabricated at a cost, speed and quality previously unobtainable.The commercial application of this project is in the area of DNA microarrays. Due to the weaknesses in the current manually machined steel pins used for printing DNA microarrays (such as extremely high manufacturing costs and low yield, poor pin-to- pin uniformity, the limited range of spot sizes deposited, waste of valuable DNA in uptake and delivery dead volumes, and deposit variability with time due to rapid tip wear), there is an urgent need for an improved printing technology. The new micromachined silicon printing product to be developed in this project will largely eliminate these drawbacks, and therefore will be well positioned for market entry as a replacement for existing products by virtue of its lower cost, superior accuracy and speed.