Shape-Shifting Composite That You Can Make At Home

In material science, thermal expansion is a very well understood concept. However, in most cases it’s regarded as somewhat of a nuisance. It’s the kind of thing that gives engineers headaches, and entire subsystems of machines are often designed specifically to combat it. But a group of students at MIT have come up with an ingeniously simple way of taking advantage of thermal expansion to create shape-changing composites.

Their project is a method of creating shape-shifting composites, called uniMorph. It works by using resistive heating (or simply ambient temperature) to change the temperature of a sandwich composite. The composite is made of two different materials, and the copper traces to heat them. The two materials themselves aren’t particularly important, what’s important is that they have vastly different thermal expansion rates.

When the composite is heated, one material will expand more or less than the other material. Depending on the relative shapes of the two materials, this causes the composite to bend or twist in predetermined ways. How much it bends, for example, is just a matter of how the layers are cut, and how much they’re heated.

The concept itself isn’t exactly new – bimetallic composites have existed for ages. We even covered a similar idea that works based on moisture content. But, the methods used for uniMorph are very well thought out. It’s very inexpensive to produce, and the students seem to have devised reliable techniques for designing the layers in order to produce a desired shape change.

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MIT’s Glass 3D Printer

How hot does your 3D printer’s hot end get? Most low cost printers heat up to 240°C (464°F) at the most because they contain PEEK which starts to get soft if you go much higher. Even a metal hot end with active cooling usually won’t go much higher than 400°C (752°F). Pretty hot, right? [MIT’s] new G3DP printer goes to 1900°F (over 1000°C) and prints optically clear glass.

By changing design and print parameters, G3DP can limit or control light transmission, reflection and refraction. The printer uses a dual heated chamber. The upper chamber acts as a 1900°F kiln while the lower chamber serves to anneal the structures. The print head is an alumina-zircon-silica nozzle.

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Dropping by the MIT Electronics Research Society

We’re in Boston this week and my first stop was at MITERS last night. This is the MIT Electronics Research Society, which started as a way to provide free access to computers for all students. Since those humble beginnings the organization has grown to include a slew of fabrication and test hardware, as well as a vibrant community that makes the group a great place to hang out.

Walking into the building you’re greeted with double doors strewn with interesting electronics and many examples of fabrication in the form of the word MITERS. The group, which is pushing 60-years of existence, feels immediately like a hackerspace where creativity and anarchy duke it out in a wild dance of experimentation. On this particular Wednesday evening we encountered a room of about 10 people working feverishly to fabricate electric racers for the PRS racing circuit in Detroit this Saturday.

Like a hackerspace, MITERS is completely member (read: student) run. There is a board that helps keep things on the rails. There is no membership fee; funding for the organization is sourced from Swapfest, a weekly flea market during the summer.

There is a strong slant toward machine shop at this hackerspace. In addition to a respectable Bridgeport CNC Mill, the machine tools and hand tools provide for almost all your fabrication needs.

What can be built in this space? How about a unibalancer? This is a single-wheeled, human-ridable vehicle that has a 7-mile cruise radius between charges. For me the most interesting feature is the deadman’s switch. You know those black rubber strips on public buses that you press for the next stop? This unibalancer has one that you need to stand on to make it go.

The hackers at MITERS excel when it comes to electric vehicles and this time of year that means the Power (Wheels) Racing Series. There are restrictions on size, and power output so the teams squeeze every bit that they can. For me, the most interesting build is based off of a pair of Ryobi electric chainsaws. The 40V batteries for these are themselves quite formidable but not used at all in the build. The team has reverse-engineered the driver circuits and written their own firmware for the STM8 microcontrollers on the boards. The chainsaws use chains to drive the two rear wheels. The entire system is monitored with XBEE-based wireless data which is displayed on a tablet.

This isn’t the only PRS build. The MITERS plan to take three different vehicles with them this weekend. The one they can’t bring is the huge electric shopping cart (with mandatory wheelie bar) which hangs from the ceiling of the space.

In addition to the formidable fabrication projects, there are a multitude of electronic projects to be seen. There is a musical tesla coil which is the best I’ve ever heard. It could easily be mistaken as a proper speaker. If you need more bass there’s a massive ceiling-mounted sub-woofer for that. And if you want a more formidable tesla coil, the parts are there.

Look hard enough and you’ll even find battle robots. This one had diamond plate that spins with a variety of nasty accoutrements intended for maximum damage of its foe. On the underside you’ll see a brushless motor used the opposite of how you might think. The shaft is attached to the locomotion frame of the bot. The underside of the spinning diamond plate has a ring of antistatic mat against which this brushless motor body spins.

Thanks to the MITERS for welcoming us in. It was a blast seeing all of the projects they’re working on!

Meetup at Artisan’s Asylum Tonight

If you’re in the Boston area, head on over to Artisan’s Asylum tonight starting at 6. They were gracious enough to open their doors for a Hackaday Meetup. Bring some hardware to show off if you can, if you can’t that’s fine as well. We’ll have a few lightning talks, some social time, and maybe an afterbar!

To wrap things up, we have covered a few projects from MITERS already, like this Power Wheels Racing build, and an electric go kart done the right way. Now that we’ve met them in person we’ll be on the lookout for a lot more awesome hacks from them.

[Thanks John for suggesting we stop by!]

Prof Gershenfeld Speaks on Fab Labs and all-things Digital

Fab Labs have developed hand-in-hand with the all-too-familiar hackerspaces that we see today. If you’re curious to discover more about their past and future, [Prof Gershenfeld], founder of the Fab Lab, and director of MIT’s Center for Bits and Atoms brings us a fresh perspective on both these fab labs and the digital world we live in.

In a casual one-hour chat on Edge, [Prof Gershenfeld] dives deeply into the concept of digital in our world. We might consider digital to be a binarized signal, an analog waveform discretized into a 0 and 1 from which all of computer architecture is built upon today. Digital doesn’t just exist in the computing sense, however; it’s a concept that has been applied to communication, computation, and, these days: personal fabrication.

[Prof Gershenfeld’s] talk may highlight coming changes in the future, but changes are already happening today. These days, fab labs and hackerspaces serve their communities in a very special way. They take “experts-of-the-field” away from universities and isolated labs, and they scatter them all over the world. With this shift, anyone can walk through their doors and build a solid foundation in fields like embedded programming and computer aided manufacturing by striking a conversation with these local experts. In a nutshell, both spaces found a culture for development of expertise far more accessible to the world community than their university counterparts.

If you can spare the hour, put on some headphones, tune in, and resume your CAD work, PCB layout, or that Arduino library. You may discover that your work is built on a number of digital principles, and that your contributions push the rest farther along the development chain towards building something awesome.

Finally, if you’re interested in taking notes on building your own fab lab, have a look at the inventorylayout, and guidelines at the CBA website.

Wireless Trackpad Looks Like Fingernail Polish

All hands are on deck over at MIT where a very handy new trackpad has been created that will be able to give users a free hand to do other tasks. The device is called the NailO and attaches to one’s thumbnail, which allows the user an easy and reportedly natural way to use a trackpad while your hands are full, dirty, or otherwise occupied.

The device reportedly works like any normal trackpad, but is about the size of a quarter and attaches to the thumbnail in such a way that it takes advantage of the natural motion of running an index finger over the thumbnail. It communicates via Bluetooth radio, and has four layers which all go hand-in-hand: an artistic covering (to replicate the look of a painted fingernail), the sensors, the circuitry, the battery, and presumably an adhesive of some sort.

Details are quite sparse, but the device is scheduled to make its debut at the Computer Human Interaction conference in Seoul, South Korea very soon. If it can be made less bulky (although it’s somewhat uncomfortable to call something smaller than a quarter “bulky”) this might be, hands down, the next greatest evolution in mouse technology since multi-touch. We have to hand it to MIT for coming up with such a unique wearable!

MIT’s Robotic Cheetah is Getting Even Scarier

Researchers over at MIT are hard at work upgrading their Robotic Cheetah. They are developing an algorithm for bounding movement, after researching how real cheetahs run in the wild.

Mach 2 is fully electric and battery-powered, can currently run at speeds of 10MPH (however they’re predicting it will be able to reach 30MPH in the future), and can even jump over obstacles 33cm tall.

We originally saw the first robotic Cheetah from Boston Dynamics in cooperation with DARPA two years ago — it could run faster than any human alive (28.3MPH) but in its tests it was tethered to its hydraulic power pack and running on a treadmill. It’s unclear if MIT’s Cheetah is a direct descendant from that one, but they are both supported by DARPA.

The technology in this project is nothing short of amazing — its electric motors are actually a custom part designed by one of the professors of Electrical Engineering at MIT, [Jeffrey Lang]. In order for the robot to run smoothly, its bounding algorithm is sending commands to each leg to exert a very precise amount of force during each footstep, just to ensure it maintains the set speed.

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Self-Assembling Origami Robots

orgami-robots-harvard

MIT engineers have developed a technique to address the challenges involved in manufacturing robots at a cheap and accessible level. Like a plant folding out its petals, a protein folding into shape, or an insect unveiling its wings, this autonomous origami design demonstrated the ability for a mechanical creature to assemble itself and walk away. The technique opens up the possibility of unleashing swarms of flat robots into hard to reach places. Once on site, the robots mobilize from the ground up.

The team behind the project used flexible print circuit boards made out of paper and polystyrene, which is a synthetic aromatic polymer typically found in the commercially sold children’s toy Shrinky Dinks™. Each hinge had embedded circuits that were mechanically programmed to fold at certain angles. Heat was applied to the composite structure triggering the folding process. After about four minutes, the hinges would cool allowing the polystyrene to harden. Some issues did arise though during the initial design phase due to the amount of electrical current running the robots, which was ten times that of a regular light bulb. This caused the original prototypes to burn up before the construction operation was completed.

In the long-term, Core Faculty Member [Robert] would like to have a facility that would provide everyday robotic assistance to anyone in the surrounding community. This place would be accessible to everyone in the neighborhood helping to solve whatever problems might arise, which sounds awfully like a hackerspace to us. Whether the person required a device to detect gas leaks or a porch sweeping robot, the facility would be there to aid the members living nearby.

A video of [Robert] and [Sam] describing the project comes up after the break:

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