Archive 22.07.2019

By Rob Matheson

An automated system developed by MIT researchers designs and 3-D prints complex robotic parts called actuators that are optimized according to an enormous number of specifications. In short, the system does automatically what is virtually impossible for humans to do by hand.  

In a paper published today in Science Advances, the researchers demonstrate the system by fabricating actuators — devices that mechanically control robotic systems in response to electrical signals — that show different black-and-white images at different angles. One actuator, for instance, portrays a Vincent van Gogh portrait when laid flat. Tilted an angle when it’s activated, however, it portrays the famous Edvard Munch painting “The Scream.” The researchers also 3-D printed floating water lilies with petals equipped with arrays of actuators and hinges that fold up in response to magnetic fields run through conductive fluids.

The actuators are made from a patchwork of three different materials, each with a different light or dark color and a property — such as flexibility and magnetization — that controls the actuator’s angle in response to a control signal. Software first breaks down the actuator design into millions of three-dimensional pixels, or “voxels,” that can each be filled with any of the materials. Then, it runs millions of simulations, filling different voxels with different materials. Eventually, it lands on the optimal placement of each material in each voxel to generate two different images at two different angles. A custom 3-D printer then fabricates the actuator by dropping the right material into the right voxel, layer by layer.

“Our ultimate goal is to automatically find an optimal design for any problem, and then use the output of our optimized design to fabricate it,” says first author Subramanian Sundaram PhD ’18, a former graduate student in the Computer Science and Artificial Intelligence Laboratory (CSAIL). “We go from selecting the printing materials, to finding the optimal design, to fabricating the final product in almost a completely automated way.”

The shifting images demonstrates what the system can do. But actuators optimized for appearance and function could also be used for biomimicry in robotics. For instance, other researchers are designing underwater robotic skins with actuator arrays meant to mimic denticles on shark skin. Denticles collectively deform to decrease drag for faster, quieter swimming. “You can imagine underwater robots having whole arrays of actuators coating the surface of their skins, which can be optimized for drag and turning efficiently, and so on,” Sundaram says.

Joining Sundaram on the paper are: Melina Skouras, a former MIT postdoc; David S. Kim, a former researcher in the Computational Fabrication Group; Louise van den Heuvel ’14, SM ’16; and Wojciech Matusik, an MIT associate professor in electrical engineering and computer science and head of the Computational Fabrication Group.

Navigating the “combinatorial explosion”

Robotic actuators today are becoming increasingly complex. Depending on the application, they must be optimized for weight, efficiency, appearance, flexibility, power consumption, and various other functions and performance metrics. Generally, experts manually calculate all those parameters to find an optimal design.  

Adding to that complexity, new 3-D-printing techniques can now use multiple materials to create one product. That means the design’s dimensionality becomes incredibly high. “What you’re left with is what’s called a ‘combinatorial explosion,’ where you essentially have so many combinations of materials and properties that you don’t have a chance to evaluate every combination to create an optimal structure,” Sundaram says.

In their work, the researchers first customized three polymer materials with specific properties they needed to build their actuators: color, magnetization, and rigidity. In the end, they produced a near-transparent rigid material, an opaque flexible material used as a hinge, and a brown nanoparticle material that responds to a magnetic signal. They plugged all that characterization data into a property library.

The system takes as input grayscale image examples — such as the flat actuator that displays the Van Gogh portrait but tilts at an exact angle to show “The Scream.” It basically executes a complex form of trial and error that’s somewhat like rearranging a Rubik’s Cube, but in this case around 5.5 million voxels are iteratively reconfigured to match an image and meet a measured angle.

Initially, the system draws from the property library to randomly assign different materials to different voxels. Then, it runs a simulation to see if that arrangement portrays the two target images, straight on and at an angle. If not, it gets an error signal. That signal lets it know which voxels are on the mark and which should be changed. Adding, removing, and shifting around brown magnetic voxels, for instance, will change the actuator’s angle when a magnetic field is applied. But, the system also has to consider how aligning those brown voxels will affect the image.

Voxel by voxel

To compute the actuator’s appearances at each iteration, the researchers adopted a computer graphics technique called “ray-tracing,” which simulates the path of light interacting with objects. Simulated light beams shoot through the actuator at each column of voxels. Actuators can be fabricated with more than 100 voxel layers. Columns can contain more than 100 voxels, with different sequences of the materials that radiate a different shade of gray when flat or at an angle.

When the actuator is flat, for instance, the light beam may shine down on a column containing many brown voxels, producing a dark tone. But when the actuator tilts, the beam will shine on misaligned voxels. Brown voxels may shift away from the beam, while more clear voxels may shift into the beam, producing a lighter tone. The system uses that technique to align dark and light voxel columns where they need to be in the flat and angled image. After 100 million or more iterations, and anywhere from a few to dozens of hours, the system will find an arrangement that fits the target images.

“We’re comparing what that [voxel column] looks like when it’s flat or when it’s titled, to match the target images,” Sundaram says. “If not, you can swap, say, a clear voxel with a brown one. If that’s an improvement, we keep this new suggestion and make other changes over and over again.”

To fabricate the actuators, the researchers built a custom 3-D printer that uses a technique called “drop-on-demand.” Tubs of the three materials are connected to print heads with hundreds of nozzles that can be individually controlled. The printer fires a 30-micron-sized droplet of the designated material into its respective voxel location. Once the droplet lands on the substrate, it’s solidified. In that way, the printer builds an object, layer by layer.

The work could be used as a stepping stone for designing larger structures, such as airplane wings, Sundaram says. Researchers, for instance, have similarly started breaking down airplane wings into smaller voxel-like blocks to optimize their designs for weight and lift, and other metrics. “We’re not yet able to print wings or anything on that scale, or with those materials. But I think this is a first step toward that goal,” Sundaram says.

By Adam Conner-Simons and Rachel Gordon

Patrick Winston, a beloved professor and computer scientist at MIT, died on July 19 at Massachusetts General Hospital in Boston. He was 76.
 
A professor at MIT for almost 50 years, Winston was director of MIT’s Artificial Intelligence Laboratory from 1972 to 1997 before it merged with the Laboratory for Computer Science to become MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL).

 
A devoted teacher and cherished colleague, Winston led CSAIL’s Genesis Group, which focused on developing AI systems that have human-like intelligence, including the ability to tell, perceive, and comprehend stories. He believed that such work could help illuminate aspects of human intelligence that scientists don’t yet understand.
 
“My principal interest is in figuring out what’s going on inside our heads, and I’m convinced that one of the defining features of human intelligence is that we can understand stories,’” said Winston, the Ford Professor of Artificial Intelligence and Computer Science, in a 2011 interview for CSAIL. “Believing as I do that stories are important, it was natural for me to try to build systems that understand stories, and that shed light on what the story-understanding process is all about.”
 
He was renowned for his accessible and informative lectures, and gave a hugely popular talk every year during the Independent Activities Period called “How to Speak.” 
 
“As a speaker he always had his audience in the palm of his hand,” says MIT Professor Peter Szolovits. “He put a tremendous amount of work into his lectures, and yet managed to make them feel loose and spontaneous. He wasn’t flashy, but he was compelling and direct. ”
 
Winston’s dedication to teaching earned him many accolades over the years, including the Baker Award, the Eta Kappa Nu Teaching Award, and the Graduate Student Council Teaching Award.
 
“Patrick’s humanity and his commitment to the highest principles made him the soul of EECS,” MIT President L. Rafael Reif wrote in a letter to the MIT community. “I called on him often for advice and feedback, and he always responded with kindness, candor, wisdom and integrity.  I will be forever grateful for his counsel, his objectivity, and his tremendous inspiration and dedication to our students.”
 
Teaching computers to think

Born Feb. 5, 1943 in Peoria, Illinois, Winston was always exceptionally curious about science, technology and how to use such tools to explore what it means to be human. He was an MIT-lifer starting in 1961, earning his bachelor’s, master’s and doctoral degrees from the Institute before joining the faculty of the Department of Electrical Engineering and Computer Science in 1970.
 
His thesis work with Marvin Minsky centered on the difficulty of learning, setting off a trajectory of work where he put a playful, yet laser-sharp focus on fine-tuning AI systems to better understand stories.
 
His Genesis project aimed to faithfully model computers after human intelligence in order to fully grasp the inner workings of our own motivations, rationality, and perception. Using MIT research scientist Boris Katz’s START natural language processing system and a vision system developed by former MIT PhD student Sajit Rao, Genesis can digest short, simple chunks of text, then spit out reports about how it interpreted connections between events.
 
While the system has processed many works, Winston chose “Macbeth” as a primary text because the tragedy offers an opportunity to take big human themes, such as greed and revenge, and map out their components.
 
“[Shakespeare] was pretty good at his portrayal of ‘the human condition,’ as my friends in the humanities would say,” Winston told The Boston Globe. “So there’s all kinds of stuff in there about what’s typical when we humans wander through the world.”
 
His deep fascination with humanity, human intelligence, and how we communicate information spilled over into what he often described as his favorite academic activity: teaching.
 
“He was a superb educator who introduced the field to generations of students,” says MIT Professor and longtime colleague Randall Davis. “His lectures had an uncanny ability to move in minutes from the details of an algorithm to the larger issues it illustrated, to yet larger lessons about how to be a scientist and a human being.”
 
A past president of the Association for the Advancement of Artificial Intelligence (AAAI), Winston also wrote and edited numerous books, including a seminal textbook on AI that’s still used in classrooms around the world. Outside of the lab he also co-founded Ascent Technology, which produces scheduling and workforce management applications for major airports.
 
He is survived by his wife Karen Prendergast and his daughter Sarah.

Making a legged robot walk is not simple. Coordinating the motion of all its joints to achieve smooth motions, close to those of real animals, requires advanced engineering and careful observation of moving animals. But what if its been extinct for 300 million years?

RobotUnion offers a total of 4M€ in equity-free funding in two open calls for startups and SMEs within the framework of the Horizon 2020 program funded by the European Commission.

SME created the Additive Manufacturing Competition to attract and introduce the younger generation to emerging technologies that manufacturers have adopted over the past few years.

Commissioned OEM Eisenmann alpha-tec regularly automates complex railway-oriented applications with industrial robots and is familiar with the latest developments on the 7th-axis market. That's why they use the world's first composite concrete 7th axis from IPR

The sophisticated integration of perception sensors, autonomous navigation, manipulation, and artificial intelligence in Swift warehouse robots enables maximum picking productivity across single pick, trays, and totes.

A lot of people have lower limb mobility impairments, but there are few wearable technologies to enable them to walk normally while performing tasks of daily living. XoSoft, a European funded project, has brought together partners from all over Europe to develop a flexible, lightweight and resource-efficient soft exoskeleton prototype.

In this episode of Robots in Depth, Per Sjöborg speaks with Andreas Bihlmaier about modular robotics and starting a robotics company.

Andreas shares how he started out in computers and later felt that robotics, through its combination of software and hardware that interacts with the world, was what he found most interesting.

Andreas is one of the founders of RoboDev, a company that aims to make automation more available using modular robotics. He explains how modular systems are especially well suited for automating low volume series and how they work with customers to simplify automation.

He also discusses how a system that can easily be assembled into many different robots creates an advantage both in education and in industrial automation, by providing efficiency, flexibility and speed.

We get a personal, behind the scenes account of how the company has evolved as well as insights into the reasoning behind strategic choices made in product development.

In a world first, Australian Centre for Robotic Vision researchers are pushing the boundaries of evolution to create bespoke, miniaturised surgical robots, uniquely matched to individual patient anatomy.

The cutting-edge research project is the brainchild of Centre PhD researcher Andrew Razjigaev, who impressed HRH The Duke of York with the Centre’s first SnakeBot prototype designed for knee arthroscopy, last November.

Now, the young researcher, backed by the Centre’s world-leading Medical and Healthcare Robotics Group, is taking the next step in surgical SnakeBot’s design.

In place of a single robot, the new plan envisages multiple snake-like robots attached to a RAVEN II surgical robotic research platform, all working together to improve patient outcomes.

The novelty of the project extends to development of an evolutionary computational design algorithm that creates one-of-a-kind, patient-specific SnakeBots in a ‘survival-of-the-fittest’ battle.

Only the most optimal design survives, specifically suited to fit, flexibly manoeuvre and see inside a patient’s knee, doubling as a surgeon’s eyes and tools, with the added bonus of being low-cost (3D printed) and disposable.

Leading the QUT-based Medical and Healthcare Robotics Group, Centre Chief Investigator Jonathan Roberts and Associate Investigator Ross Crawford (who is also an orthopaedic surgeon) said the semi-autonomous surgical system could revolutionise keyhole surgery in ways not before imagined.

Professor Crawford stressed the aim of the robotic system – expected to incorporate surgical dual-arm telemanipulation and autonomous vision-based control – was to assist, not replace surgeons, ultimately improving patient outcomes.

“At the moment surgeons use what are best described as rigid ‘one-size-fits-all’ tools for knee arthroscopy procedures, even though patients and their anatomy can vary significantly,” Professor Crawford said.

He said the surgical system being explored had the potential to vastly surpass capabilities of current state-of-the-art surgical tools.

“The research project aims to design snake-like robots as miniaturised and highly dexterous surgical tools, fitted with computer vision capabilities and the ability to navigate around obstacles in confined spaces such as the anatomy of the human body,” Professor Crawford said.

“Dexterity is incredibly important as the robots are not only required to reach surgical sites but perform complicated surgical procedures via telemanipulation.”

Professor Roberts said the research project was a world-first for surgical robotics targeting knee arthroscopy and would not be possible without the multi-disciplinary expertise of researchers at the Australian Centre for Robotic Vision.

“One of the most exciting things about this project is that it is bringing many ideas from the robotics community together to form a practical solution to a real-world problem,” he said.

“The project has been proceeding at a rapid pace, mainly due to the hard work and brilliance of Andrew, supported by a team of advisors with backgrounds in mechanical engineering, mechatronics, aerospace, medicine, biology, physics and chemistry.”

Due to complete his PhD research project by early 2021, Andrew Razjigaev graduated as a mechatronics engineer at QUT in 2017 and has been a part of the Centre’s Medical and Healthcare Robotics Group since 2016.

The 23-year-old said: “Robotics is all about helping people in some way and what I’m most excited about is that this project may lead to improved health outcomes, fewer complications and faster patient recovery.

“That’s what really drives my research – being able to help people and make a positive difference. Knee arthroscopy is one of most common orthopaedic procedures in the world, with around four million procedures a year, so this project could have a huge impact.”

Andrew said he hoped his work would lead to real-world development of new surgical tools.

“Surgeons want to do the best they can and face a lot of challenges,” he said. “Our objective is to provide surgeons with new tools to be able to perform existing surgery, like knee arthroscopy, more efficiently and safely and to perhaps perform surgery that is simply too difficult to attempt with today’s tools.

“It’s also incredibly cool to use evolution in my work! There’s no question we’re witnessing the age-old process – the only difference being it’s happening inside a computer instead of nature.”

• The process starts with a scan of a patient’s knee. With the supervision of a doctor, the computer classifies the regions for the SnakeBots to reach in the knee (green area) and regions to avoid (red area).
• The resulting geometry makes a 3D environment for the SnakeBots to compete in the simulated evolution. It enables a number of standard SnakeBot designs to be tested and scored on how well they perform – namely how well they manoeuvre to sites inside a patient’s knee. The black lines in the test show some of the trajectories a SnakeBot took to manoeuvre to those sites.
• The evolutionary computational design algorithm kicks in, continually creating new generations of SnakeBots, re-testing and killing off weaker variants until one survives, uniquely matched to an individual patient’s anatomy.  The SnakeBot that can safely reach those targets with more dexterity wins the battle of evolution and claims the optimal design.
• The optimal SnakeBots are generated into 3D models to be 3D printed as low-cost, disposable surgical tools unique to each patient.
• They are now ready to be deployed for surgery! The micro SnakeBots are attached to a larger, table-top robotic platform (like the RAVEN II) that positions them for entry into surgical incision sites.
• It is expected that two SnakeBots are fitted with surgical instruments at their tips to enable a surgeon to perform dual-arm teleoperated surgical procedures.
• A third SnakeBot in the multi-bot system will have a camera installed at its tip. This camera system will be used by a robotic vision system to map a patient’s body cavity so that the robot can be steered towards the areas of interest and away from delicate areas that should be avoided. It will track the two arms and surgical area simultaneously, working as the eyes of the surgeon.

Find out more about the work of the Centre’s Medical and Healthcare Robotics Group in our latest annual report.

Instead of a new eyepiece or objective lens, the four-meter reflector telescope is being outfitted with about 5,000 fiber optic sensor-equipped, pencil-sized robots. The 5,000 robots will fit inside ten wedge-shaped petals.

Much like other industries, the automotive industry is changing. With the increase in the variety of vehicle models, variants, and derivatives being produced and the shorter product life cycles in the automotive industry.

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

ABB’s research team will work on the TMC campus with medical staff, scientists and engineers to develop non-surgical medical robotics systems, including logistics and next-generation automated laboratory technologies.