Ammonia oxidation in a microreactor

How do you make a microreactor?

Microreactors, like integrated circuits or microchips, can be made from silicon wafers. They are made using a complicated process called photolithography. Photolithography was developed in the 1800s to print labels directly on tin sheets used to make cans. It evolved into a process used today that allows pictures to be printed easily in newspapers, books, and magazines. It later evolved into a process used for building integrated circuits. Now it's evolved again for use in building microreactors.

In a nutshell, microreactor (and microchip) photolithography involves using strong, corrosive chemicals called etchants to cut either into the silicon wafer or into materials coated on top of the silicon. The trick is to use one etchant that cuts into silicon but not the coated material, and another etchant that cuts into the coated material but not the silicon. The photo part of the process involves printing a 'picture' of the microreactor onto the coated silicon before starting the etching processes. We told you it was complicated!

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If you're really interested, check out the junior chemical engineer's version of this page.

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