Nanoindentation: A no-nonsense explanation

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Nanoindentation has become a popular method for characterizing materials at nano-micron scales. Those unfamiliar with this method are wary. Is the method accurate? How does it measure? Why is it important? I will try to answer some of these questions regarding nanoindentation in this article. New users will gain an understanding of the advancement that nanoindentation has brought to material characterization. It will also help us develop an understanding of many applications where nanoindentation is helping researchers do what they couldn’t do before.

Material characterization with nanoindentation requires three steps: 1) The nanoindenter needs an actuation and sensing system to measure the force applied and depth caused by the indenter, 2) The measurements need to be calibrated for the environment such as thermal drift, frame stiffness, and 3) Material being tested determines experimental design, such as for thin film polymers or hard metals.

Once these three steps are addressed, we can accurately measure modulus, hardness, creep, in addition to many more properties. This can all be completed without any sample preparation and in a matter of seconds. Conversely, conventional measurement systems could take weeks and months to obtain these properties. This is what makes nanoindentation so powerful, it is not only accurate but also very efficient. Nanoindentation also proves to be a superior technique providing depth dependent mechanical measurements as well as measurement on very thin samples that are not possible with other techniques.

The flow chart in the picture summarizes what comprises a nanoindentation test. Each segment of this process is important and if not performed correctly will lead to results that are essentially inaccurate.

So how do we make sure that we make accurate measurements every time we run our tests? The operator just has to set up the experiment by selecting the site of indentation and the system does the rest. Nanoindentation is such a simple technique that you don’t need to be a nanoindentation expert to run these experiments.

Hopefully, this article was useful as an introduction to the Nanoindentation. I will continue to provide more articles on each step to build upon the understanding of nanoindentation. Please feel free to contact me with any questions.

P.S. – Please leave your email in the comments below if you would like a copy of the 'starter kit presentation' for a basic understanding of nanoindentation. Please feel free to use it for educational outreach.