SpherIndent: An open-source Python software for calibration, analysis and visualization of spherical nanoindentation experiments
SpherIndent is a modular, open-source software package with graphical user interface (GUI) for analysis of quasi-static spherical indentation experiments conducted in single-step or multi-step loading sequences.
All components are developed in Python programming language with the GUI built on Tkinter. The software package is essentially constructed using libraries including NumPy, Pandas, SciPy, Sklearn, Matplotlib, and OpenCV. Data storage, from raw to processed and analyzed data (including figures) is handled via Pickle with traceability, efficient retrieval and sharing in mind. SpherIndent only uses tabular data from indentation experiments (time-depth-force), image files from peripheral equipment (i.e., scanning electron microscopes – SEM-), or self-generated files.
SpherIndent includes:
- Calibration routines to determine machine compliance based on indentation of reference materials,
- Calibration routines to determine the tip geometry (i.e., tip radius and cone angle) via tip-area function calculation or tip image analysis,
- Data conditioning routines to eliminate thermal drift, compute zero-point offset, and correct for machine compliance effects,
- Analysis routines to extract various material metrics of interest (e.g., Hertz and Oliver-Pharr elastic moduli, dissipation indices, maximum shear stress at first pop-in, stress-strain pairs) from SII and MSI indentation tests.
- Create a Conda environment from the provided 'spherindent_env.yml file: conda env create -f spherindent_env.yml -n [your_env_name]
- Activate the environment: conda activate [your_env_name]
- Create a Conda environment from the provided 'spherindent_env.yml file: conda env create -n [your_env_name]
- Activate the environment: conda activate [your_env_name]
- Install dependencies: pip install -r requirementsSpherIndent.txt
To run this code, follow these steps:
- Open Spyder and create a new project or open an existing one.
- Open the spherIndent.py script.
- Make sure you select the Conda environment created earlier in Tools>Preferences>Python Interpreter.
- Make sure you change the plotting of your Spyder from inline to automatic (inline exhibits odd behavior).Tools>Preferences>IPython console>Plotting>Graphics backend>Automatic
- Run the script by clicking on the "Run" button or pressing F5.
- Use the GUI.
- Open VSCode and open the folder containing your project.
- Make sure you have the Python extension installed.
- Open the spherIndent.py script.
- Make sure you have selected the correct Python interpreter (i.e., the one from your Conda environment) by clicking on the Python version in the bottom left corner of the VSCode window.
- Run the script by clicking on the "Run Code" button or pressing F5.
- Use the GUI.
Alternatively, you can also run the script from the terminal/command prompt:
python spherIndent.py
The Background.jpg file is not needed to run SpherIndent. Download it and use it with VS Code. Sometimes it works with Spyder, but it does not affect the software.
Examples are provided in the associated peer-reviewed publication [1]. The examples leverage the public dataset in [2].
Certain commercial equipment, software, instruments, and materials are identified in this document. Such identification does not imply recommendation or endorsement by the National Institute of Standards and Technology, nor does it imply that the products identified are necessarily the best available for the purpose.
This work was performed with funding from the CHIPS Metrology Program, part of CHIPS for America, National Institute of Standards and Technology, U.S. Department of Commerce.
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Please contact Nicolas A. Alderete (nicolas.alderete@nist.gov, ORCID: 0000-0002-2145-8825) or Yvonne B. Gerbig (yvonne.gerbig@nist.gov, ORCID: 0000-0002-8947-4215) for questions.
[1] Alderete, N.A., Gerbig, Y.B., SpherIndent: An open-source python software for calibration, analysis and visualization of spherical nanoindentation experiments, (Under review). doi: 10.18434/mds2-4080.
[2] Gerbig, Y.B., Alderete, N.A., Demonstration dataset for open-source SpherIndent analysis and calibration software for spherical nanoindentation experiments, NIST Public Data Repository, doi: 10.18434/mds2-4051.
The work was done under the CHIPS project Characterization of Nano-to-Microscale Process-Induced Thermo-Mechanical Changes in Heterogeneously Integrated Microelectronics