Microscale reaction devices

A system comprising:

• i) a microdroplet;
• ii) first and second microdroplet transport channels in a silicon substrate, wherein said channels comprise a first silicon layer, a silicon nitride layer, and a second silicon oxide layer, said channels having a depth between 0.35 and 50 μm, having a width between 50 and 1000 μm, and connecting to a reaction region;
• and
• iii) a series of etched aluminum heating elements arrayed along said first and second transport channels, wherein said series of heating elements are configured so as to provide differential heating of said microdroplet by said heating elements.

A device comprising:

• i) a first housing portion comprising silicon;
• ii) a microdroplet transport channel in said first housing portion, wherein said channel comprises a first silicon layer, a silicon nitride layer, and a second silicon oxide layer, said transport channel having a depth between 0.35 and 50 μm, having a width between 50 and 1000 μm, and connecting to a reaction region;
• iii) a second housing portion bonded to and aligned with said first housing portion thus creating an assembled housing, wherein said second housing portion is selected from the group consisting of silicon, quartz or glass;
• and
• iv) a series of etched aluminum heating elements in said assembled housing arrayed along said microdroplet transport channel, wherein said series of heating elements are configured so as to provide differential heating.