By David L. Chandler
Years ago, MIT Professor Neil Gershenfeld had an audacious thought. Struck by the fact that all the world’s living things are built out of combinations of just 20 amino acids, he wondered: Might it be possible to create a kit of just 20 fundamental parts that could be used to assemble all of the different technological products in the world?
Gershenfeld and his students have been making steady progress in that direction ever since. Their latest achievement, presented this week at an international robotics conference, consists of a set of five tiny fundamental parts that can be assembled into a wide variety of functional devices, including a tiny “walking” motor that can move back and forth across a surface or turn the gears of a machine.
Previously, Gershenfeld and his students showed that structures assembled from many small, identical subunits can have numerous mechanical properties. Next, they demonstrated that a combination of rigid and flexible part types can be used to create morphing airplane wings, a longstanding goal in aerospace engineering. Their latest work adds components for movement and logic, and will be presented at the International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS) in Helsinki, Finland, in a paper by Gershenfeld and MIT graduate student Will Langford.
Their work offers an alternative to today’s approaches to contructing robots, which largely fall into one of two types: custom machines that work well but are relatively expensive and inflexible, and reconfigurable ones that sacrifice performance for versatility. In the new approach, Langford came up with a set of five millimeter-scale components, all of which can be attached to each other by a standard connector. These parts include the previous rigid and flexible types, along with electromagnetic parts, a coil, and a magnet. In the future, the team plans to make these out of still smaller basic part types.
Using this simple kit of tiny parts, Langford assembled them into a novel kind of motor that moves an appendage in discrete mechanical steps, which can be used to turn a gear wheel, and a mobile form of the motor that turns those steps into locomotion, allowing it to “walk” across a surface in a way that is reminiscent of the molecular motors that move muscles. These parts could also be assembled into hands for gripping, or legs for walking, as needed for a particular task, and then later reassembled as those needs change. Gershenfeld refers to them as “digital materials,” discrete parts that can be reversibly joined, forming a kind of functional micro-LEGO.
The new system is a significant step toward creating a standardized kit of parts that could be used to assemble robots with specific capabilities adapted to a particular task or set of tasks. Such purpose-built robots could then be disassembled and reassembled as needed in a variety of forms, without the need to design and manufacture new robots from scratch for each application.
Langford’s initial motor has an ant-like ability to lift seven times its own weight. But if greater forces are required, many of these parts can be added to provide more oomph. Or if the robot needs to move in more complex ways, these parts could be distributed throughout the structure. The size of the building blocks can be chosen to match their application; the team has made nanometer-sized parts to make nanorobots, and meter-sized parts to make megarobots. Previously, specialized techniques were needed at each of these length scale extremes.
“One emerging application is to make tiny robots that can work in confined spaces,” Gershenfeld says. Some of the devices assembled in this project, for example, are smaller than a penny yet can carry out useful tasks.
To build in the “brains,” Langford has added part types that contain millimeter-sized integrated circuits, along with a few other part types to take care of connecting electrical signals in three dimensions.
The simplicity and regularity of these structures makes it relatively easy for their assembly to be automated. To do that, Langford has developed a novel machine that’s like a cross between a 3-D printer and the pick-and-place machines that manufacture electronic circuits, but unlike either of those, this one can produce complete robotic systems directly from digital designs. Gershenfeld says this machine is a first step toward to the project’s ultimate goal of “making an assembler that can assemble itself out of the parts that it’s assembling.”
A team of EPFL researchers has developed tiny 10-gram robots that are inspired by ants: they can communicate with each other, assign roles among themselves and complete complex tasks together. These reconfigurable robots are simple in structure, yet they can jump and crawl to explore uneven surfaces. The researchers have just published their work in Nature.
Individually, ants have only so much strength and intelligence. However, as a colony, they can use complex strategies for achieving sophisticated tasks to survive their larger predators.
At EPFL, researchers in NCCR Robotics Professor Jamie Paik’s Laboratory have reproduced this phenomenon, developing tiny robots that display minimal physical intelligence on an individual level but that are able to communicate and act collectively. Despite being simple in design and weighing only 10 grams, each robot has multiple locomotion modes to navigate any type of surface. Collectively, they can quickly detect and overcome obstacles, pass them and move objects much larger and heavier than themselves. The related research has been published in Nature.
Robots modeled on trap-jaw ants
These three-legged, T-shaped origami robots are called Tribots. They can be assembled in only a few minutes by folding a stack of thin, multi-material sheets, making them suitable for mass production. Completely autonomous and untethered, Tribots are equipped with infrared and proximity sensors for detection and communication purposes. They could accommodate even more sensors depending on the application.
“Their movements are modeled on those of Odontomachus ants. These insects normally crawl, but to escape a predator, they snap their powerful jaws together to jump from leaf to leaf”, says Zhenishbek Zhakypov, the first author. The Tribots replicate this catapult mechanism through an elegant origami robot design that combines multiple shape-memory alloy actuators. As a result, a single robot can produce three distinctive locomotive motions – crawling, rolling and jumping both vertically and horizontally – just like these creatively resilient ants.
Roles: leader, worker and explorer
Despite having the same “anatomy”, each robot is assigned a specific role depending on the situation. ‘Explorers’ detect physical obstacles in their path, such as objects, valleys and mountains. After detecting an obstacle, they inform the rest of the group. Then, the “leader” gives the instructions. The ‘workers’, meanwhile, pool their strength to move objects. “Each Tribot, just like Odontomachus ants, can have different roles. However, they can also take on new roles instantaneously when faced with a new mission or an unknown environment, or even when other members get lost. This goes beyond what the real ants can do” says Paik.
Future applications
In practical situations, such as in an emergency search mission, Tribots could be deployed en masse. And thanks to their multi-locomotive and multi-agent communication capabilities, they could locate a target quickly over a large surface without relying on GPS or visual feedback. “Since they can be manufactured and deployed in large numbers, having some ‘casualties’ would not affect the success of the mission,” adds Paik. “With their unique collective intelligence, our tiny robots are better equipped to adapt to unknown environments. Therefore, for certain missions, they would outperform larger, more powerful robots.” The development of robots for search-and-rescue applications and the study of collective robotics are key research areas within the NCCR Robotics consortium, of which Jamie Paik’s lab is part.
In April, Jamie Paik has presented her reconfigurable robots at the TED2019 Conference in Vancouver. Her talk is available here.
Literature
Zhenishbek Zhakypov, Kazuaki Mori, Koh Hosoda and Jamie Paik, Designing minimal and scalable insect-inspired multi-locomotion millirobots, Nature
DOI: 10.1038/s41586-019-1388-8
In this episode, join our interviewer Andrew Vaziri at Promat 2019, the largest expo for manufacturing and supply chain professionals in North and South America. Andrew interviews a handful of companies which provide warehouse fulfillment robots that can autonomous pick and place items. Our guests explain how advances in AI have made autonomous picking possible. They also talk about the unique technologies they use to stand out in a crowded field of competing products.
The guests in the order they appear are:
Vince Martinelli, Head of Product and Marketing, RightHand Robotics
Jim Liefer, CEO, Kindred
Pete Blair, VP of Marketing, Berkshire Grey
Sean Davis, Technical Product Manager, Osaro
Erik Nieves, CEO, Plus One Robotics
See video of each robot picking items on our YouTube page:
Links