Soft Lithography
The basic process of soft lithography includes 3 steps: 1) design of a pattern to be printed on a mask; 2) transfer of the pattern onto a photoresist layer that covers a glass surface by using a light source through the mask ; 3) Imprinting the pattern into polymers such as PDMS, which can be sealed with a coverslip to form microchannels. According to the light source used in step 2, the resolution of the pattern is in the range of micrometers (UV source) to nanometers (near field light or e-beams). Recent progress in the lithography process has enhanced its efficiency. For example, methods developed by George Whitesides and other people reduced the cycling time of the entire process to less than a day.
