BACKGROUND:  Typical printing pins are susceptible to variations in pin surface, print surface, printing speed, and environmental conditions such as humidity. Precise control over these conditions, along with pre-printing, can reduce the degree of inconsistency in printed spot size and volume. However, the precise control can require a skilled user to supervise the process. Furthermore, the rate of printing is slowed down, decreasing throughput and efficiency of the printing process. Printed spot size can become irregular, requiring a lower density of printed spots. Pre-printing to a dummy surface is standard protocol to remove excess material from the exterior of the printing pins prior to starting the intended printing. However, pre-printing wastes material, and causes a delay which lowers printing throughput and efficiency.

INNOVATION:  Printing pins are improved by selective coating and/or treatment, distinctively differentiating the interior and the exterior of liquid channel and thus preventing the rogue liquid on the exterior surface. Greater consistency in printed spot size and volume reduces sensitivity to the printing environment and conditions, reducing the need for strict user scrutiny over the spot printing process. The improvement further eliminates the need for pre-printing and avoids droplet waste. Thus, printing throughput is improved, increasing printing efficiency and saving time. Because the improvement can be applied to most types of printing pins, economic savings can be realized without retrofitting, upgrading or retooling. The improvement likewise can be applied to custom made printing pins. A variety of surface coating and/or treatment options are available for achieving improvements while preserving chemical resistance, durability, and low interaction to biological molecules.

POTENTIAL APPLICATIONS 

• Improved printing devices (contact printing, non-contact printing, injection printing, droplet printing, bubble printing, and microarray printing)

ADVANTAGES

• Eliminates need for pre-printing, reduces print time and improves printing throughput
• Avoids solution waste by minimizing excess liquid pickup
• Allows consistent solution deposit size and volume for improved printing results and higher density of printed spots
• Applies to most existing commercially available printing pins and equipment, allowing for easy and economical adoption
• Relaxes the need for strict printing control by reducing sensitivity to adverse environments, conditions, gradual deviations, and accidental deviations

DEVELOPMENT-TO-DATE:  All major aspects of the invention have been constructed, experimentally tested, and verified.

Reference: UCLA Case No. 2006-007