Robotics

New technique for mass-producing microbots inspired by pop-up books and origami

New technique for mass-produci...
Inspired by origami and children's pop-up books, Harvard engineers have pioneered a means of mass-producing bee-sized flying microrobots from flat laminated sheets
Inspired by origami and children's pop-up books, Harvard engineers have pioneered a means of mass-producing bee-sized flying microrobots from flat laminated sheets
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Plan drawing of the Mobee and scaffold
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Plan drawing of the Mobee and scaffold
Mobee and scaffold in flat, pre-assembled form
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Mobee and scaffold in flat, pre-assembled form
Close-up of the Mobee and scaffold in flat, pre-assembled form
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Close-up of the Mobee and scaffold in flat, pre-assembled form
Mobee and scaffold part-unfolded
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Mobee and scaffold part-unfolded
An assembled Mobee and scaffold
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An assembled Mobee and scaffold
Close-up of the tiny Mobee flying robot
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Close-up of the tiny Mobee flying robot
Inspired by origami and children's pop-up books, Harvard engineers have pioneered a means of mass-producing bee-sized flying microrobots from flat laminated sheets
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Inspired by origami and children's pop-up books, Harvard engineers have pioneered a means of mass-producing bee-sized flying microrobots from flat laminated sheets
Half and half: a drawing and photo of the Mobee and scaffold in plan view
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Half and half: a drawing and photo of the Mobee and scaffold in plan view
Detailed CAD drawing of the Mobee, in which the 18 layers can be seen
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Detailed CAD drawing of the Mobee, in which the 18 layers can be seen
Flat and assembled - at a glance you'd hardly spot the difference
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Flat and assembled - at a glance you'd hardly spot the difference
A Mobee assembly detail
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A Mobee assembly detail
Detail of a typical Mobee hinged joint
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Detail of a typical Mobee hinged joint
Folded joints lock into place with an apparently simple mechanism - though nothing is simple at such a small scale
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Folded joints lock into place with an apparently simple mechanism - though nothing is simple at such a small scale

Inspired by origami and children's pop-up books, Harvard engineers have pioneered a means of mass-producing bee-sized flying microrobots. The breakthrough mechanizes the already state-of-the art process of making Harvard's Mobee robots by hand, by mass producing flat assemblies by the sheet which can be folded and assembled in a single movement. The technique, which cunningly exploits existing machinery for making printed circuit boards, can theoretically be applied to a multitude of electromechanical machines.

The art of flat

Prototypes of the mass-produced Mobee (short for Monolithic Bee) consist of 18 laminated layers of carbon fiber, polymers and ceramics, laser cut into an intricate form that incorporates 22 folding joints, and housed in a dedicated assembly scaffold (which itself has an additional 115 folding joints).

It's these folding joints - hinges, basically - that allow the robot to be assembled in a single movement. The scaffold is crucial to this process, providing two horizontal plates which can be pulled apart, erecting the Mobee in the process.

The new process allows for scores of robots to be manufactured at once on a single sheet.

Machines making machines: automating the artisanal

The switch from hand-made robots to automated manufacture has all but eliminated failures. Only months ago, the Harvard team was folding and gluing parts by hand using techniques they had developed in-house. "You'd take a very fine tungsten wire and dip it in a little bit of superglue," said Pratheev Sreetharan, co-developer of the technique with J. Peter Whitney. "Then, with that tiny ball of glue, you'd go in under a microscope like an arthroscopic surgeon and try to stick it in the right place."

State-of-the-art this process may have been, but only 15 out of every 100 robots manufactured actually worked. Automation not only eliminates human error, but increases the options basket in terms of both materials and manufacturing processes. "The ability to incorporate any type and number of material layers, along with integrated electronics, means that we can generate full systems in any three-dimensional shape," said principal investigator Rob Wood. "We've also demonstrated that we can create self-assembling devices by including pre-stressed materials."

The manufacturing is so accurate, in fact, that the team is at pains to measure it, though Sreetharan says it is "better than 5 microns everywhere".

Flat and assembled - at a glance you'd hardly spot the difference
Flat and assembled - at a glance you'd hardly spot the difference

Diffusion: automating the making of small, complex machines

Because the process is so adept at embedding electronics into machinery, it is particularly suited to the manufacture of small electromechanical machines, or those with tightly integrated electronics. Keeping the weight of the Mobees down is so important, the design team cannot afford to introduce structural elements that cannot also contribute to the robot's electronic functioning. The entire product, scaffold included, is only the size of a US quarter and weighs only 90 mg, or a mere three thousandths of an ounce.

That the process builds upon the techniques used to created printed circuit boards is potentially of great significance. Harvard claims that the tools needed to adopt the technique are already widely used, which means the technique might see rapid diffusion - should the demand for products prove widespread. Harvard has filed numerous patent applications associated with the process, and is working with business to "identify disruptive applications in a range of industries."

An excellent video (and I do not use the term lightly) showing animations and video footage of the assembly of the Mobee is below.

Source: Harvard

Pop-up Fabrication of the Harvard Monolithic Bee (Mobee)

3 comments
Arf
That is quite slick!
Gregg Eshelman
It didn\'t show what they coat the wings with, nor did it show the completed thing flying. Can it actually fly with a tethered power source or is it just a technology demonstration to show they can make a pair of wings flap? What would be even better is if they could make the assembly scaffold reusable. As it is, it\'s like using a dry dock to build one ship then scrapping the dry dock.
Anthony Wood
Now all they need to do is print solar cells onto the laminate & then you have an onboard power source. Also field effect power generation to take advantage of lighting and power circuits within buildings, just remember that this is just a well developed proof of concept.