In one way or another, each of us uses origami skills to shape simple things from paper sheets. In robotics, origami is a different and revolutionary field that deals with lightweight and highly versatile robots. It is the field where origami techniques and skills merge aiming to build compact form robots by bending and laying parts together.

This time, my aim is to explore four ideas that shape the origami field in robotics right now and try to understand the materials, components and building techniques. It is about a foldable sheet project, robots with origami wheels, transformer robots and origami drones.

Prelude to origami

The first play land of origami was a simple sheet of paper. And because it is flexible and springy, the manipulation is not difficult even for a 3-year-old child.

Complex origami forms involve successive folds of paper while the volume or surface area is shrinking with each fold. Tens of books provide a large variety of designs and step-by-step instructions to understand and manipulate the sheet.

Why we want to build origami robots?
There are several reasons to build origami robots. The first cause is due to the possibility of miniaturization and space creation. This is the root of significant improvements in reducing the weight and costs of the robots. A simple crab-walker bot made from paper and polystyrene can work in places where humans cannot go.

Another reason to start building origami robots in mass is the store packaging and shipping services. Organizing the components to fit onto the flat sheet lead into a small space needed to place things and easy shipping to the final consumer.

Traditional robots with bolts and rigid chassis are a very good platform for many situations where robots should replace the humans. But these rigid platforms cannot fully meet the needs for specific conditions or extreme environments where the robot is expected to perform unspecified and a variety of different tasks.

There are just three of the reasons that make me think of the future through the foldable robots perspective. The list is much longer and with interesting features for almost any industry where the robots are present nowadays.

A little bit history and a little bit of present

In a traditional and educational way, origami is described as paper folding. The origin of origami art is traced back to the sixth century where folded paper models were used for ceremonial occasions in Japan.

In our days, over 1,500 years later, in the modern world, origami is considered paper sculpture where the designers look to build much more complex things. Inside origami communities, the users change ideas and discuss about the best paper with the excellent properties to fold or how to build their own paper. These discussions would not take place if the designers do not want to build the most complicated models and push the limits of creation.

Four ideas that shape the origami art in robotics

We should not stop for anything in this world because that day when we stop may be the day before our success. The best way to see very good results in the origami area is to continue to research and innovate.

I am already thinking about the day when I can place an order to buy a foldable robot able to clean my house, climb the stairs, clean the trash, and go out with my pet. And if I consider all the projects started in our days, this puzzle of tasks will be solved soon.

Foldable sheet idea

One big idea is to use uniform and small foldable sheet to build versatile robots. Like a LEGO kit, we can build adaptable robots by snapping together a set of sheets built from semi-rigid materials.

What I described above was already designed inside the labs of MIT and Harvard by a group of scientists and engineers. The group combines origami techniques with electrical engineering with the result of a flexible and intelligent sheet of a programmable material able to turn into absolutely anything. The foldable sheet of semi-rigid material can automatically transform into an origami boat or airplane. And this is just the beginning.

What is the secret of these two different transformations? Applying a different electrical signal, the intelligent material can take a large variety of shapes. It is a simple solution applied easily and with minimum costs.

In another way, NASA has already applied the idea of origami paper sheet in space missions. The NASA engineers build light and foldable solar panels that look more like a blooming flower than a simple sheet of panel.

In this way, they build more components that are portable and reduce the costs of transportation.

And if you think a little more, we can combine the intelligent programmable material with built-in solar panels to power the robots. In this way, we can build eco-friendly robots that work autonomously for a long period measured even in years.

Origami wheels

What is the idea with origami wheels? The researchers from Seoul National University, South Korea, have designed and tested robotic wheel prototypes engineered with origami technique. The origami technique is called ‘magic ball pattern’ and is used to create folded paper spheres.

The robot wheel prototype is designed to change its radius by increasing or decreasing the volume. A large wheel can climb things while a smaller size wheel squeezes under obstacles. And to not forget an important detail, the diameter of the wheel grows and shrinks automatically.

Why we need origami wheels?

In addition to the property to pick up or let down the robot, an origami wheel is able to speed the robot and make the platform strong when it expands and shrinks in size automatically.

Another reason to use this kind of wheels is the control system. With just a few actuators, we have the possibility to control the size of the wheel.

In space missions, the humans are usually taken by surprise. Attaching origami wheels to a rover can make the difference between a successful and a failed mission.

The materials and mechanical systems

We have to dive deep into the origami structure to understand how things work. From a simple wheel to a transforming wheel is a long way. The solution was found in a complex system with kinematics capabilities that change the diameter of the wheel.

The researchers do not reinvent the wheel. They have to drive mechanisms with special design able to deform the wheel to reach the desired design in a very small space. This simplified process of transformation reduces the cost, decrease the difficulties, and reduce the time of manufacturing.

Transformer robots

Is there anyone expecting to see a robot transforming into Optimus Prime?

In the field of a fully transforming robot, the idea is to build a robot capable to build itself and walk away autonomously. In addition, all these features are inspired by origami techniques.

The scientists from Harvard University build one of the first transforming robots inspired by origami. The result is an alien robot capable to take the form of a car or truck, something similar to Transformer movie. Of course, there are places for improvements and increase the technical level, but at this moment, the robot is capable to assemble itself.

New materials for foldable robots

The field of foldable robots has specific needs in terms of materials and technologies. A sheet of paper and plastic with attached battery and motors is not enough to build a transformer bot. The engineers have developed new “shape memory polymers” and printable robot components that react to temperature to form a robot that fold itself without human intervention.

All these technologies are in an early stage and needs improvements. For example, the shape memory polymers that react like a muscle need several minutes to assemble from scratch and walk.

Components?
Do you think that you can buy an Arduino microcontroller, several motors, a bunch of sensors, wires and that is all the components for a transforming robot? No. These components have their limits and cannot be used in the classic style. To build a foldable robot we need to invent or redesign the sensors, capacitors, motors, inductors, and actuators.

A good start is already done with a new type of motor that comes in two parts. One part of the motor is a permanent magnet that the robot folds itself around it. The second part is a set of four electromagnetic coils located under the surface that the robot operate and react to the magnetic fields generated by the first part.

Another project, other technologies. A group of MIT researchers builds foldable electronic components using polyester coated with aluminum. The result is a sensor that looks more like an accordion and less than a classical sensor. Each accordion folds has integrated a resistor. This means that the total resistance of the sensor is changing when each of the accordion folds is folded or unfolded.

The actuator that moves the robot is a foldable coil with a pair of iron cylinders that are magnetized by an electrical current.

Another way to make things move is to use shape memory polymers and a bit of heat. The polymers can be printed on one side of a hinged substrate and heated to bend the structure. Depending on the etching connectors that are flexible, the amount of bend can be controlled on each side.

The potential of this material is huge. They can be printed out of a large variety of materials and then used with other hardware for a foldable structure.

Origami drone

A foldable drone can do wonders in applications such as military surveillance, traffic monitor, weather and climate mapping, search and rescue, and agriculture.

Why? Because it is cheap, it folds and fits in small places; the flight autonomy is increased due to a small weight and more. In other words, a small piece of plastic and metal can unfold deploy themselves and ready to fly in seconds.

It is impressive that we do not need special materials to build foldable drones. What we need is a remarkable idea. The team at EPFL and NCCR Robotics design drone arms made of fibreglass and light inelastic polyester. The arms fold up into the shape of a trapezoid, and when are not in use, all four arms are wrapped horizontally around the body of the drone.

The arms unfold itself helped by the force generated by the robots. When the arms are fully extended, an upper section located on each segment moves horizontally and locks the arms with small magnets that hold the parts in place. This is an ingenious system inspired by origami techniques, and unfortunately it’s not an open-source system (it has been patented by the designers.)

Do you need a conclusion?

I analyze these projects to discover the applications, materials and the technologies used to build origami robots. After many hours of reading and documentation, I have one simple conclusion: the origami art has a huge potential to grow in robotics.

References:
Robotic Origami Folding
Origami Wheel Transformer
Shape-shifting robots
Scientists Engineer Origami-Inspired Transformer