Maskless array synthesizer

In an alternative approach developed by NimbleGen (http //www.nimblegen. com/, Madison, WI), arrays are built using photodeposition chemistry based on a maskless array synthesizer (MAS). The MAS system is a high-density DNA fabrication instrument that uses a maskless light projector as a virtual mask instead of the physical chromium masks used by Affymetrix. The virtual mask is an array of hundreds of thousands of individually addressable aluminum mirrors on a computer chip. These mirrors function as virtual masks that reflect the desired pattern of UV light and are controlled by the computer. 

---