This Small Business Innovation Research (SBIR) Phase I project is a new approach to building a microarray (biochip) printing system. The result is expected to be a proven design capable of spotting sub-picoliter droplets of biofluids onto substrates at a tenfold to hundredfold speed improvement over existing systems. A second design will be a very low cost (under $4,000) and reliable printer suitable for the tens of thousands of biotechnology labs worldwide. The research objectives are to use modeling and systematic testing to optimize an electrohydrodynamic droplet ejection mechanism based on Taylor instability and adapt it for microarray printing. Although the droplet emission phenomenon has been observed in a few research papers, it has not been adequately characterized and adapted to the requirements of a high capacity microarray printing system used in a production environment. The Phase I research would involve a study of the droplet ejection mechanism, including voltage patterns, nozzle shape, grounding grids, dielectric constants of materials, and substrate separation from nozzle. These results will be incorporated into proprietary designs for the microarray printers. The commercial application of this project is in the area of microarrays. Clinical genomic applications (disease diagnosis, drug sensitivity testing, and forensics) will require production of standard and custom microarrays (biochips) by the millions. Although ongoing genetic and proteomic research is making these applications possible, an important missing link is a technology for a large improvement in the speed, cost, and reliability of the mass production of microarrays. This project expects to address this market niche
