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Should My Robot be More or Less Squishy?

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Areas of Science
Time Required
Short (2-5 days)
Familiarity with VoxCAD software is required for this project. We recommend completing the Science Buddies introductory VoxCAD project first.
Material Availability
This project requires the free VoxCAD software, and a computer running Microsoft® Windows®.
Very Low (under $20)
No issues

Ben Finio, Ph.D., Science Buddies

  • Windows is a registered trademark of Microsoft Corporation.
*Note: For this science project you will need to develop your own experimental procedure. Use the information in the summary tab as a starting place. If you would like to discuss your ideas or need help troubleshooting, use the Ask An Expert forum. Our Experts won't do the work for you, but they will make suggestions and offer guidance if you come to them with specific questions.

If you want a Project Idea with full instructions, please pick one without an asterisk (*) at the end of the title.


In our introductory VoxCAD project, we provided a template with four materials: two active materials that expand and contract in the physics sandbox mode, and two passive materials — one hard and one soft. The project mentioned material properties, but it did not go into much detail — you just used the default settings from the template. Changing the material properties can drastically change how your robots behave. Engineers must take material properties into account when designing robots and other machines. For example, they might want to use a strong metal material for the legs of a robot to support its weight, but a soft rubbery material for the feet to help absorb impact when it walks.

This document will explain what the different material properties are, what they mean, and how to change them. But because this is an abbreviated project idea, we will not provide specific directions for how to run new tests or simulations with your robot designs. Deciding exactly what to do will be up to you.

To start, click on the Palette tab in the bottom-right corner of the VoxCAD window. Within the Palette tab are three sub-tabs: Appearance, Model, and Physical. These are where you edit the material properties, as shown in Figure 1.

Palette tab that can be found in the VoxCAD program

The palette tab has three sub-tabs which are appearance, model, and physical. The sub-tabs are used to edit the material properties.

Figure 1. The Palette tab is in the bottom-right corner of VoxCAD and has three sub-tabs above it: Appearance, Model, and Physical. Select the material you want to edit from the list in the upper right, then edit its properties using the settings in these three tabs.

Important: Be sure you have the material you want to edit selected from the materials listed on the right-hand side of the screen.

The Appearance tab enables you to change the color of a material. This only affects how a material looks and does not change its other physical properties.

The Model tab lets you select the mathematical model used to calculate how a material deforms (stretches, bends, and compresses). We recommend sticking with the "Linear" model, which means that your materials will always "bounce back" to their original shape and never "break."

The Physical tab lets you set additional physical properties of the material.

Here is a complete list of properties you can change, assuming you are using the "Linear" option in the Model tab. These are only brief explanations — you can do more research about each topic if you want to know more.

To test what these settings do, change them one at a time, and by small amounts. For example, the coefficients of thermal expansion are originally set to +0.01 and -0.01. But if you change them to +100 and -100, your simulation may change so dramatically that it will be hard to understand what happened. It is more realistic to change them to +0.02 and -0.02 to start.

If you want to use more than the four basic materials, you can also create new materials by clicking the Add Material button in the Palette tab, represented by a plus (+) symbol. Watch the tutorial video in the Bibliography to learn about some of the more advanced options in the Palette tab.

Remember, because this is an abbreviated project idea, exactly what you do now is up to you. Here are a few ideas:

If you want to learn more about VoxCAD, you can check out our abbreviated project ideas on changing the physics settings and designing energy-efficient robots.


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Global Connections

The United Nations Sustainable Development Goals (UNSDGs) are a blueprint to achieve a better and more sustainable future for all.
This project explores topics key to Industry, Innovation and Infrastructure: Build resilient infrastructure, promote sustainable industrialization and foster innovation.


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General citation information is provided here. Be sure to check the formatting, including capitalization, for the method you are using and update your citation, as needed.

MLA Style

Science Buddies Staff. "Should My Robot be More or Less Squishy?" Science Buddies, 20 Nov. 2020, https://www.sciencebuddies.org/science-fair-projects/project-ideas/Robotics_p018/robotics/robot-simulator-VoxCAD?from=Blog. Accessed 26 Feb. 2024.

APA Style

Science Buddies Staff. (2020, November 20). Should My Robot be More or Less Squishy? Retrieved from https://www.sciencebuddies.org/science-fair-projects/project-ideas/Robotics_p018/robotics/robot-simulator-VoxCAD?from=Blog

Last edit date: 2020-11-20
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