Build a Simple Robot with a Tensegrity Structure
30-60 min
Ages 8+
What Will You Make?
Build this surprisingly resilient structure, then make it move.
Tensegrities are known for being squishable and bouncy — but that’s not all they do. The word “tensegrity” — a combination of the words “tension” and “integrity” — was coined by architect Buckminster Fuller, who also invented the geodesic dome. But the structures do more than just bounce. This tensegrity robot is based on prototypes developed by computer scientist John Rieffel and his students at Union College in Schenectady, New York.
Once you’ve built your tensegrity structure, you can quickly put together a circuit to make your robot move using littleBits, electronic modules that snap together magnetically.
What Will You Learn?
You will learn to make careful cuts to construct a tensegrity structure and then use electronics to motorize your creation.
Cut straws
Step 1
Cut 6 pieces of straw to no more than about 5″ long.
Step 2
On each straw, cut a slit on either end, making sure that the slits are aligned (i.e., both vertical). The slits should be ¼” deep — enough to hold the rubber band in place, but not so much that the straw begins to weaken and bend.
Connect straws
Step 3
Line up 2 straws and wrap a small rubber band loosely around each end of the pair.
Step 4
Do the same to a second pair of straws and slide them perpendicularly between the first 2 straws to form an “X” shape.
Add more straws
Step 5
Take the last 2 straws and wrap a small rubber band around one end. Slide them through the intersection of the other straws so that they’re perpendicular to the first 2 pairs, and then wrap a small rubber band around the other end.
Stretch rubber bands
Step 5
Twist one pair of straws so their slits are horizontal and facing you, with one above the other.
Step 6
Stretch a long rubber band from the horizontal slit of the upper straw, up and over a pair of perpendicular straws, and to the other end of the straw, passing it through all 4 slits.
Repeat
Step 7
Repeat Steps 5 and 6 with the all the remaining straws
Step 8
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Cut and adjust
Step 9
Cut away the small rubber bands so that the tensegrity structure springs open.
Step 10
Adjust the pairs of straws so they’re parallel and not touching.
Assemble littleBits
Step 11
Now assemble the littleBits electronic circuit that will make your tensegrity bot go:
Plug the power module (or “Bit”) into the battery.
Attach the dimmer switch module for turning the voltage up or down.
Connect the bar graph module to the dimmer switch. This is a Bit with 5 rows of miniature LEDs; as more power goes through it, more LEDs light up.
Finish
Step 12
Attach one or more wires. The wire modules are short, so use 2 or 3 to make sure your robot has room to move.
Finally, add the vibrating motor. This is a small disc, about the size of a pill, with 2 thin wires attaching it to a magnetic base.
What Is Happening Here?
How It Works
A tensegrity structure can flex, stretch, compress when dropped or pressed, and then spring back into shape. It also has a high degree of compliance, which means it won’t harm people or equipment around it. That, together with its resilience, makes tensegrity a useful framework for robots that need to withstand jolts or squeeze and twist themselves through irregular spaces.
The directions for assembling this six-strut tensegrity structure out of drinking straws and rubber bands are based on a tensegrity icosahedron holiday ornament project from Bre Pettis that appeared on the Make: website in 2007.
Make It Move
The circuit consists of a tiny vibrating motor, a dimmer switch to make it run faster or slower, and a bar graph indicator that shows how much power you’re supplying to the motor. Attaching the motor to the tensegrity structure will make the structure vibrate and move across the table.
To try out your tensegrity robot, attach your electronic circuit to your straw model. Situate the vibrating motor so that none of the electronics get in the way of the tensegrity structure’s motion.
Decide where you’d like to attach the disc end of your motor. Use tape or another adhesive to hold it onto one of the straws. Stretch the motor wire along the straw and attach the motor base and wire base to it.
Turn on the motor and slowly increase the power with the dimmer switch. You’ll start to see the rubber bands vibrate in sympathy, and your tensegrity robot should start to shimmy along the table. See if you can steer it to the right and left by adjusting the power.
If your robot doesn’t move, try attaching the motor higher or lower on the structure. Moving the robot’s center of gravity a little off-center can help overcome its inertia. Now that the robot works, experiment with placing the motor in different locations on the tensegrity structure — in the center, off on one corner — to see which position produces the most reliable and interesting movements. Varying the speed and placement of the motor will produce different kinds of motion, giving the robot a kind of physical intelligence.
Troubleshooting Tips:
If the motor turns on but the tensegrity doesn’t move, flip the tensegrity around so a different side is on the bottom. You can also try moving the motor closer or farther away from the end of the straw.
Find a smooth, flat surface for the tensegrity to glide around.
What Is Next?
Make It Without littleBits
In her book Making Simple Robots, 2nd edition, Kathy Ceceri uses a mini vibrating disk motor, a 3V coin battery, conductive tape, and a binder clip to create the circuit that moves the robot. How can you make the robot move with the materials you have?
Take It Further
While this simple tensegrity robot moves through vibration, advanced tensegrity robots move by contracting their cables and changing shape so they can roll. For an even greater challenge, think about how you could design your robot to do the same. Or break out of the prototyping stage and build a new version of this circuit without using littleBits. Starting here, you’ll be well on your way to making your own advanced tensegrity robots.
Want to make your tensegrity steerable? Add a dimmer switch that lets you make the vibration motor go faster or slower
About the Book
Making Simple Robots, 2nd Edition by Kathy Ceceri is based on the idea that anybody can build a robot! That includes kids, educators, parents, and anyone who didn’t make it to engineering school. If you can cut, fold, and tape a piece of paper to make a tube or a box, you can build a no-tech robotic part.
In fact, many of the models in this book are based upon real-life prototypes — working models created in research labs and companies. What’s more, if you can use the apps on your smartphone, you can quickly learn to tell robots what to do using free, online, beginner-level software like MIT’s Scratch and Microsoft MakeCode.
The projects in this book which teach you about electric circuits by making jumping origami frogs with eyes that light up when you get them ready to hop. You’ll practice designing all-terrain robot wheel-legs with free, online Tinkercad software, and you’ll create files ready for 3D printing. You’ll also learn to sew — and code — a cyborg rag doll with a blinking electronic “eye.”
Each project includes step-by-step directions and clear illustrations and photographs. Along the way, you’ll learn about the real research behind the DIY version, find shortcuts for making projects easier when needed, and get suggestions for adding to the challenge as your skill set grows.
Suggested Add-On: Making Simple Robots Starter Pack
This companion starter pack has all the electronics you’ll need and then some for the projects in Making Simple Robots, 2nd Edition, by Kathy Ceceri (book required for projects).
Materials:
- Drinking straws (6) (TIP: Keep some spare straws on hand while you’re working. If a straw bends, you’re better off replacing it than trying to fix it.)
- Rubber bands, roughly 5" long (6)
- Rubber bands, shorter than 5" (6)
- Masking tape, glue dots, double-sided mounting tape or other removable adhesive
- littleBits modules: Power, #p1; Dimmer, i6; Bargraph, o9; Wire, w1 (1 or more); and Vibration motor, o4
- Scissors
Maker Camp Project Standards
Based on NGSS (Next Generation Science Standards)
NGSS (Next Generation Science Standards)
The Next Generation Science Standards (NGSS) are K–12 science content standards. Learn more.Forces and Motion
- 3-PS2-3. Ask questions to determine cause and effect relationships of electric or magnetic interactions between two objects not in contact with each other.
- HS-PS4-5. Communicate technical information about how some technological devices use the principles of wave behavior and wave interactions with matter to transmit and capture information and energy.
CCSS (Common Core State Standards)
The Common Core is a set of high-quality academic standards in mathematics and English language arts/literacy (ELA).Measurement & Data
- Grades K-2
- CCSS.MATH.CONTENT.K.MD.A.1 Describe measurable attributes of objects, such as length or weight. Describe several measurable attributes of a single object.
- CCSS.MATH.CONTENT.1.MD.A.1 Order three objects by length; compare the lengths of two objects indirectly by using a third object.
- CCSS.MATH.CONTENT.1.MD.A.2 Express the length of an object as a whole number of length units, by laying multiple copies of a shorter object (the length unit) end to end; understand that the length measurement of an object is the number of same-size length units that span it with no gaps or overlaps.
- CCSS.MATH.CONTENT.2.MD.A.1 Measure the length of an object by selecting and using appropriate tools such as rulers, yardsticks, meter sticks, and measuring tapes.
- CCSS.MATH.CONTENT.2.MD.A.2 Measure the length of an object twice, using length units of different lengths for the two measurements; describe how the two measurements relate to the size of the unit chosen.
- CCSS.MATH.CONTENT.2.MD.A.3 Estimate lengths using units of inches, feet, centimeters, and meters.
- CCSS.MATH.CONTENT.2.MD.A.4 Measure to determine how much longer one object is than another, expressing the length difference in terms of a standard length unit.
- Grades 3-5
- CCSS.MATH.CONTENT.3.MD.B.3 Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. Solve one- and two-step "how many more" and "how many less" problems using information presented in scaled bar graphs.
- CCSS.MATH.CONTENT.4.MD.A.1 Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit.
- CCSS.MATH.CONTENT.4.MD.C.5 Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement.
- CCSS.MATH.CONTENT.5.MD.A.1 Convert among different-sized standard measurement units within a given measurement system (e.g., convert 5 cm to 0.05 m), and use these conversions in solving multi-step, real world problems.
- CCSS.MATH.CONTENT.5.MD.C.3 Recognize volume as an attribute of solid figures and understand concepts of volume measurement.
Ratios & Proportional Relationships
- Middle School
- CCSS.MATH.CONTENT.6.RP.A.1 Understand the concept of a ratio and use ratio language to describe a ratio relationship between two quantities.
- CCSS.MATH.CONTENT.6.RP.A.3 Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
- CCSS.MATH.CONTENT.7.RP.A.1 Compute unit rates associated with ratios of fractions, including ratios of lengths, areas and other quantities measured in like or different units.
- CCSS.MATH.CONTENT.7.RP.A.2 Recognize and represent proportional relationships between quantities.
CCSS (Common Core State Standards)
The Common Core is a set of high-quality academic standards in mathematics and English language arts/literacy (ELA).English Language Arts Standards » Science & Technical Subjects
- Middle School
-
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- CCSS.ELA-LITERACY.RST.6-8.1 Cite specific textual evidence to support analysis of science and technical texts.
- CCSS.ELA-LITERACY.RST.6-8.3 Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.
- CCSS.ELA-LITERACY.RST.6-8.4 Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 6-8 texts and topics.
- CCSS.ELA-LITERACY.RST.6-8.5 Analyze the structure an author uses to organize a text, including how the major sections contribute to the whole and to an understanding of the topic.
- CCSS.ELA-LITERACY.RST.6-8.6 Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text.
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- High School
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- CCSS.ELA-LITERACY.RST.9-10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions.
- CCSS.ELA-LITERACY.RST.9-10.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.
- CCSS.ELA-LITERACY.RST.9-10.4 Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 9-10 texts and topics.
- CCSS.ELA-LITERACY.RST.9-10.5 Analyze the structure of the relationships among concepts in a text, including relationships among key terms (e.g., force, friction, reaction force, energy).
- CCSS.ELA-LITERACY.RST.9-10.6 Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text, defining the question the author seeks to address.
- CCSS.ELA-LITERACY.RST.11-12.1 Cite specific textual evidence to support analysis of science and technical texts, attending to important distinctions the author makes and to any gaps or inconsistencies in the account.
- CCSS.ELA-LITERACY.RST.11-12.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.
- CCSS.ELA-LITERACY.RST.11-12.4 Determine the meaning of symbols, key terms, and other domain-specific words and phrases as they are used in a specific scientific or technical context relevant to grades 11-12 texts and topics.
- CCSS.ELA-LITERACY.RST.11-12.5 Analyze how the text structures information or ideas into categories or hierarchies, demonstrating understanding of the information or ideas.
- CCSS.ELA-LITERACY.RST.11-12.6 Analyze the author's purpose in providing an explanation, describing a procedure, or discussing an experiment in a text, identifying important issues that remain unresolved.
ISTE Standards (International Society for Technology in Education)
The ISTE Standards provide the competencies for learning, teaching and leading in the digital age, providing a comprehensive roadmap for the effective use of technology in schools worldwide.1.1 Empowered Learner
- Summary: Students leverage technology to take an active role in choosing, achieving, and demonstrating competency in their learning goals, informed by the learning sciences.
- 1.1.a Students articulate and set personal learning goals, develop strategies leveraging technology to achieve them and reflect on the learning process itself to improve learning outcomes.
- 1.1.b Students build networks and customize their learning environments in ways that support the learning process.
- 1.1.c Students use technology to seek feedback that informs and improves their practice and to demonstrate their learning in a variety of ways.
- 1.1.d Students understand the fundamental concepts of technology operations, demonstrate the ability to choose, use and troubleshoot current technologies and are able to transfer their knowledge to explore emerging technologies.
1.2 Digital Citizen
- Summary: Students recognize the rights, responsibilities and opportunities of living, learning and working in an interconnected digital world, and they act and model in ways that are safe, legal and ethical.
- 1.2.a Students cultivate and manage their digital identity and reputation and are aware of the permanence of their actions in the digital world.
- 1.2.b Students engage in positive, safe, legal and ethical behavior when using technology, including social interactions online or when using networked devices.
- 1.2.c Students demonstrate an understanding of and respect for the rights and obligations of using and sharing intellectual property.
- 1.2.d Students manage their personal data to maintain digital privacy and security and are aware of data-collection technology used to track their navigation online.
1.3 Knowledge Constructor
- Summary: Students critically curate a variety of resources using digital tools to construct knowledge, produce creative artifacts and make meaningful learning experiences for themselves and others.
- 1.3.a Students plan and employ effective research strategies to locate information and other resources for their intellectual or creative pursuits.
- 1.3.b Students evaluate the accuracy, perspective, credibility and relevance of information, media, data or other resources.
- 1.3.c Students curate information from digital resources using a variety of tools and methods to create collections of artifacts that demonstrate meaningful connections or conclusions.
- 1.3.d Students build knowledge by actively exploring real-world issues and problems, developing ideas and theories and pursuing answers and solutions.
1.4 Innovative Designer
- Summary: Students use a variety of technologies within a design process to identify and solve problems by creating new, useful or imaginative solutions.
- 1.4.a Students know and use a deliberate design process for generating ideas, testing theories, creating innovative artifacts or solving authentic problems.
- 1.4.b Students select and use digital tools to plan and manage a design process that considers design constraints and calculated risks.
- 1.4.c Students develop, test and refine prototypes as part of a cyclical design process.
- 1.4.d Students exhibit a tolerance for ambiguity, perseverance and the capacity to work with open-ended problems.
1.5 Computational Thinker
- Summary: Students develop and employ strategies for understanding and solving problems in ways that leverage the power of technological methods to develop and test solutions.
- 1.5.a Students formulate problem definitions suited for technology-assisted methods such as data analysis, abstract models and algorithmic thinking in exploring and finding solutions.
- 1.5.b Students collect data or identify relevant data sets, use digital tools to analyze them, and represent data in various ways to facilitate problem-solving and decision-making.
- 1.5.c Students break problems into component parts, extract key information, and develop descriptive models to understand complex systems or facilitate problem-solving.
- 1.5.d Students understand how automation works and use algorithmic thinking to develop a sequence of steps to create and test automated solutions.
NGSS MS.Engineering Design
The Next Generation Science Standards (NGSS) are K–12 science content standards.- MS-ETS1-1. Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.
- MS-ETS1-2. Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
- MS-ETS1-3. Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
- MS-ETS1-4. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process such that an optimal design can be achieved.
NGSS HS.Engineering Design
The Next Generation Science Standards (NGSS) are K–12 science content standards.- HS-ETS1-1. Analyze a major global challenge to specify qualitative and quantitative criteria and constraints for solutions that account for societal needs and wants.
- HS-ETS1-2. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.
- HS-ETS1-3. Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
- HS-ETS1-4. Use a computer simulation to model the impact of proposed solutions to a complex real-world problem with numerous criteria and constraints on interactions within and between systems relevant to the problem.
NGSS 3-5.Engineering Design
The Next Generation Science Standards (NGSS) are K–12 science content standards.- 3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
- 3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
- 3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
