Tag Archives: deployablestructures


MIT has published a paper entitled Programmable Matter by Folding (full article) that describes paper that can fold itself into a variety of shapes. The paper is covered by is divided into triangular sections that are joined by a network of thin nitinol actuators that contract under voltage. At the center of each section is a magnet that is used to retain the paper’s shape.

While I’m sure MIT had bigger plans for this tech (Well if it was the Media Lab, perhaps not.), I immediately thought that this was the perfect thing for synthetic plants. I’ve been thinking about how nitinol wires, or at least something like them, could deform a paper but thought that the being able to compresses only about 4% was a problem. When I first saw this video, I thought they were using something else besides nitinol, but they’re not. The trick they they used to get 180 degree bending is folding and annealing the 100μm foil so that the nitinol will remember the folded shape. Once it cooled, the foil is manually flattened, and then reheating the foil with electrical current will cause it return to the folded shape.

Guess it’s time to get some nitinol sheets.

Synthetic Plants

I’ve been thinking more about solar plants recently. I like how these projects combine both form and function. I’ve been thinking about what I’d like in one of these, and how one would be made. First, the power being collected by the solar cells needs to go somewhere. It could just feed back into the device, which is exactly what happens with plants, but part of me likes the idea of having the sculpture(?) have a practical use as well. If I want practicality, then USB ports for charging an iPod or a phone that I don’t have would be nice. At least one port, but four would be more than plenty. I’m leaning towards the solar cells charging some li-ion or nicad battery coupled with something like a Minty Boost.

The second feature I’ve been hammering the previous electronic plants I’ve looked at is the movement, specifically heliotropism (i.e. sun tracking). It’s an interesting feature, and it would increase the power to the photovoltaics. I don’t like the idea of the hearing servos move, so that means nitinol wires, which also have the quality of more closely resembling natural motion by simply expanding and contracting. The next question then becomes, what form would the motion would take?

If rigid photovoltaics are used, then panel could be mounted to a universal joint with the two outside corners independently controlled by nitinol. The other idea is to use flexible photovoltaics and hopefully no hinges and joints.

Another interesting idea is to think about deployable structures, which would seem to imply the use of flexible photovoltaics. It’s not exactly the heliotropism I was thinking of, but it would be cool if the “leaves” opened up in the day, tracked the light, and then closed at night.

Doing all of this nitinol might be kind of difficult. Heating nitinol causes it to contract in the 3 – 5 % range, doesn’t seem like much. This also means that for a deployable structure, it needs to collapse when the wires are extended,

Will I actually build this? Probably not, but it is something I’ve been thinking about. Perhaps it would give me an excuse to visit Noisebridge.