Ammonia oxidation in a microreactor

Continuous or batch?

The microreactor for this project is a continuous type, but there is another option. For analytical applications, researchers are designing and testing batch microreactors. As with continuous microreactors, the advantages of using a batch microreactor (as opposed to a conventional device) are derived directly from the microreactor's small size.

One example comes from work done at Penn State. They have developed a method for fabricating polystyrene batch reactors with volumes as low as 0.4 picoliter (that's 0.0000000000004 liter). These reactors have been used for electrochemical monitoring of single cell samples. The advantage is that any compounds produced by the single cell (after stimulation) will not be diluted by extraneous material. The reactors are made using a template; the template is a silicon wafer that has undergone photolithography.

A second example of a batch microreactor is a DNA analyzer being developed at the University of Michigan. Its sample size is not quite as small - 120 nanoliters, or 0.000000120 liter - but that's still orders of magnitude smaller than conventional analyzers. The microreactor is made using a bonded assembly consisting of a silicon chip and glass chip.

 For more information on these batch microreactors, please consult these references.