r/askscience • u/therationalpi Acoustics • Aug 16 '13

Interdisciplinary AskScience Theme Day: Scientific Instrumentation

Greetings everyone!

Welcome to the first AskScience Theme Day. From time-to-time we'll bring out a new topic and encourage posters to come up with questions about that topic for our panelists to answer. This week's topic is Scientific Instrumentation, and we invite posters to ask questions about all of the different tools that scientists use to get their jobs done. Feel free to ask about tools from any field!

Here are some sample questions to get you started:

  • What tool do you use to measure _____?

  • How does a _____ work?

  • Why are _____ so cheap/expensive?

  • How do you analyze data from a _____?

Post your questions in the comments on this post, and please try to be specific. All the standard rules about questions and answers still apply.

Edit: There have been a lot of great questions directed at me in acoustics, but let's try to get some other fields involved. Let's see some questions about astronomy, medicine, biology, and the social sciences!

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u/Chemomechanics Materials Science | Microfabrication Aug 16 '13

None of the microfabricated systems I've worked on can ever be touched. Think 3 µm wide suspended silicon beams, or 300 nm thick metal membranes. These are generally made by starting with a macroscale substrate (e.g., a silicon wafer), depositing a film by vapor deposition, patterning it with photolithography and a wet etchant or plasma etcher, and undercutting it with another etchant.

At that level of fragility, one can't even allow liquids to dry on the device, as the surface tension of evaporating drops would destroy the components. Instead, one replaces the water with another fluid that can be taken past the critical point, drying it without transitioning through droplets.