Research on printing stability and continuity by quill pin

Contact printing by quill pins is one of important methods for fabrication of microarrays on biochips and microplates. A stable and continuous printing has crucial effects on the sample point uniformity of the microarrays. In this paper, the printing process was divided into four stages: sample dipping, sample transferring, contact printing and spot extension. Then, the criteria used for stable and continuous printing on the substrates were presented. By modeling the fluid mechanics of the liquid cone in the quill pin, the quantitative effects of the pin contour geometry on the kinematics and shapes of the liquid cone have been analyzed theoretically. The results show that the liquid cone height, the slit inclination, the pin slit width coefficient and the contact angle of the slit surface have dominate influences on the stability and continuity of printing. Finally, the microarray fabrication platform of quill pin printing by robot was developed. The experimental results demonstrated the theoretical analysis and satisfied the biological application requirements.