An electric motor is typically built in a factory full of stamped steel and copper wire, but MIT researchers recently produced their own linear motor — it was cheap, fully functioning and produced from a 3D printer.
The outcome stems from teaching the printer new tricks.
The team used a commercial extrusion system that could handle the full caboodle of materials, including plastic filament, magnetic pellets and conductive silver ink and produced all of the structural parts: printed coils, permanent magnets, a flexible spring and soft magnetic cores.
The only thing left to do was magnetize the printed magnets.
The resulting linear actuator was able to move back and forth by 318 micrometers at 41.6 hertz. The produced solenoids (coils) generated magnetic intensity up to 2.03 millitesla and the permanent magnets reached 71 millitesla.
These numbers are small, but the proof of concept is anything but.
Other 3D-printed motors rely on store-bought magnets and copper coils, but these mechanical necessities were printed in-house and on the same platform.
Though this won’t power a car in the very near future, the big-picture implications could be significant. Printed motors and other electromechanical systems may one day be printed completely on-site. This could reduce costs and reliance on complicated global supply chains for fields including robotics and space-based manufacturing.
When designing complex machinery like spacecraft or drones, engineers typically use best- and worst-case scenario thought processes — kind of like what’s the best we can get out of this part and what’s the minimum this part can do?
This kind of thinking, however, doesn’t account for things that happen in the real world, like battery life depleting faster in the heat or software behaving differently in different conditions.
For this reason, a team from MIT and the University of Zurich created a framework that allows for probability. So instead of factoring in that a certain motor will last five hours, the framework says sometimes it lasts five hours, sometimes it lasts four and at times it lasts six hours.
Each part comes now with a probability profile that allows the designers to run “what if” simulations that factor in the messiness of the real world.
Testing was run on drone design and the results were unexpected. For example, a specific battery setup appeared poor in worst-case models but performed very well on average. Without the new probability-based considerations, it may have been dismissed altogether.
This means engineers can design smarter, safer and more dependable systems, which is imperative in situations where failure is not an option. Embracing uncertainty has made design more realistic and much more of service.
The research team will be speaking on their paper at the IEEE Conference on Decision and Control (CDC) 2025.
In Earth’s low orbit, where debris travels at about 27,000 kilometers per hour, even a grain of dust can hit like a bullet. That’s a big problem for satellites and spacecraft.
Researchers from Texas A&M University and MIT have developed a super-thin plastic film that could help solve this problem.
Designed with space protection in mind, the material can absorb and heal from micrometeoroid-scale impacts at speeds over 750 meters per second (almost the speed of a bullet). When hit with a microprojectile in the lab, they absorb the impact, close up more than 80 percent of the hole and keep going strong.
This isn’t your everyday plastic wrap; it’s made from Diels-Alder polymers — molecules with bonds that break and reform under heat and pressure.
While it’s not meant to stop bullets, this self-repairing film offers a glimpse into the future of lightweight, resilient materials for extreme environments — like orbiting satellites, deep-space missions or protective layers in harsh industrial settings.
The film is only nanometers thick, super strong, flexible and smart enough to patch itself up mid-impact.
The first step in building any robot is to decide what you want it to do. While most of the robot’s abilities will be unlocked with clever machine learning and artificial intelligence algorithms, you need to set your robot up for success with the right mechanical features.
LISTEN TO THE DEEP DIVE
For a human eyeball, nice and round, turn to embedding light-sensitive receptors directly onto the surface of a 3D sphere like the team from the Hong Kong University of Science and Technology, UC-Berkeley and the Lawrence Berkeley National Laboratory.
You could also add a narrow bandgap semiconductor as a photosensing material — then your robot could see in the dark with infrared light sensing. In lieu of realism, you could turn to any number of sensors to have your robot “see”:
Distance sensors and gauges – maybe an ultrasonic range finder or laser measurement sensor. Positioning sensor – room navigation or indoor localization might come in handy. A GPS system or other live tracking devices will help your robot find its way around.
Thermal imaging sensors or pressure sensors are also an option.
Facial recognition – that’s some machine learning pre-programming.
LEGS
Want to jump? Forget biomimicry. Researchers at the UC Santa Barbara use an actuator system based on elasticity. It’s a spring with rubber bands and carbon fiber slats used to shoot the bot into the air.
Or keep the biomimicry but add hydraulic systems and electric motors a la Boston Dynamics’ Atlas.
You could leave humanity behind and go the marsupial route. German engineering firm Festo took it one further and developed the BionicKangaroo.
A “tendon” in its robotic leg drives it forward and captures energy on landing. The impact drives the legs into position for the next leap on its spring-loaded legs.
GRAPHICS: Abjad Design
Stanford University engineers developed a “stereotyped nature-inspired aerial grasper” or SNAG, bird-shaped feet that can perch on any branch.
WINGS
Go classic with drone design and choose rotary wings that spin to create lift and thrust like a helicopter. These are best for hovering, vertical takeoff and changing direction quickly.
Maybe you’d rather the classic plane look and have room for a runway or launcher. Fixed wings generate lift by moving through the air and offer higher speed, longer endurance and greater stability, though your robot will be at the mercy of the weather conditions.
You could even turn to the flapping wings of insects and birds. There are complex transmission systems using gears and motors available from the Harvard team that developed a solar-powered tiny robot styled after a honey bee. A team at the University of Bristol developed a tiny flying robot that flaps its wings more efficiently than an insect, using an electrostatic “zipping” mechanism (their words).
HANDS
What kind of hand does your robot need? Do you want the classic gripper, optimized for delicacy or accuracy? Or is a suction cup plenty?
How many joints does your robot arm need? You’re not limited by human anatomy here.
Many robot hands come with sensors packed into their fingertips only, but an MIT team built a robotic finger with sensors providing continuous sensing along the finger’s entire length, allowing it to accurately identify an object after grasping it just one time.
Researchers at Columbia Engineering developed a highly dexterous robot hand that can operate in the dark. It uses tactile sensors rather than vision to manipulate objects.
A face mask developed during the pandemic to reduce stress and anxiety is evolving into a digital tool that can continue to serve its original purpose in a post-mask environment.
One of the winning teams of the 2022 Women to Impact venture of King Abdullah University of Science and Technology (KAUST) created a face mask called takeAbreath that monitors the wearer’s stress and anxiety levels. It then uses gaming technology to recommend breathing exercises to reduce any anxiety and stress identified.
The team – Anna-Maria Pappa, Sofia Dias and Leontios Hadjileontiadis of Khalifa University and Sahika Inal of KAUST – conceived the product during the height of the pandemic and are adapting the technology to offer relief for those who struggle with stress and anxiety.
Next generation
of face masks
People around the world wore masks in their daily lives during the pandemic to help prevent infection. Now, a new kind of mask might help diagnose illness. Read more›››
Engineers from MIT and Harvard say their new prototype can produce a COVID-19 test result in 90 minutes. The wearer breathes normally into the mask, and droplets produced by exhaling and coughing collect on a pad. The wearer then presses a button to activate the test. A small bit of water is released, flowing through the pad and rehydrating freeze-dried cells that react to the presence of coronavirus markers.After about 90 minutes, a colored line indicates whether the result is positive or negative. It looks like a pregnancy test. The team used a typical N95 mask and the results were published in Nature Biotechnology.This technology had been developed to detect other viruses such as Ebola. The MIT and Harvard teams have further plans for the technology. “We’ve demonstrated that we can freeze-dry a broad range of synthetic biology sensors to detect viral or bacterial nucleic acids, as well as toxic chemicals, including nerve toxins. We envision that this platform could enable next-generation wearable biosensors for first responders, health-care personnel and military personnel,” MIT researcher James Collins tells MIT news.Meanwhile, researchers at Khalifa University have been working on the NavaMASK, a sustainable and environmentally friendly mask made with a bio-based polymer that can be composted and integrated back into the ecosystem. “The NavaMASK not only addresses the pressing issue of mask waste but also highlights the importance of using renewable resources and minimizing environmental impact,” Shadi Hasan, director of KU’s Center for Membranes & Advanced Water Technology, tells KUST Review.‹‹‹ Read less
“In the end we do this to help people,” Pappa, who in 2019 was one of MIT Technology Review’s Innovators Under 35, tells KUST Review.
And now the team is adapting the technology into an app that, in its initial phase, begins with a simple breath into a phone and will eventually operate concurrently with wearable biosensors.
Users breathe into smartphone microphones, which capture the breath rate. The wearable biosensors read the wearers’ biological responses to stress. After the data is analyzed, the app recommends personalized breathing games to calm the heart rate and the wearer’s stress.
Breathing correctly, the team members say, is a skill people have to learn. They compare it to an athlete building endurance.
“Breathing in for seven seconds is not easy,” Dias says.
The team is working through some challenges around the many different brands of mobile devices and hopes to have a marketable product soon.
“Clearly, many development stages are on the horizon, yet we are hoping in one year to have the conceptualized idea transformed to a product. This will only happen with the intensive research efforts that we are currently undertaking, the support from Khalifa University and potential angel/venture funders,” Hadjileontiadis tells KUST Review.
The ultimate goal is for every breath to be a tool to “unlock our mindset toward stressless living,” Hadjileontiadis says.
According to the World Health Organization, stress and depression increased by 25 percent in the first year of the pandemic alone. It was so prevalent that it prompted 90 percent of countries surveyed to include mental health and psychosocial support in their COVID-19 response plans.
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