This is some seriously cool research. Scientists at the EPFL (Ecole Polytechnique Federale de Lausanne) have made tiny, tiny, tiny robots using shape memory alloys, or SMA’s for short. They weigh less than 4 grams and move like an inchworm!
Unlike regular robots that feature rigid structures and electric actuators, the researchers opted to take more of an origami like approach — so much so, they call it robogami. Their very first attempt was years ago, and was rather large. Since then they’ve shrunk it down to about the size of a compact flash card. The way it works is quite simple. SMA’s shrink when heated (either externally heated or by an internal current) and in doing so, produce extremely high forces.
So by patterning these in a shape (like that of an inchworm) the researchers are able to trigger each “limb” separately to induce movement. They can also jump seven times their height thanks to the super high power-density of SMA’s.
Continue reading “SMA Robot Jumps 7 Times Its Height, Weighs Nothing”
[Maurizio] was having some reception issues with his wireless internet and set out to add an external antenna to the USB dongle (translated). He had previously poked around inside of the Nokia internet key to find that the internal antenna was a flexible circuit substrate wrapped around a plastic box that made contact with main circuit board via a spring connector. This plastic frame is just right for mounting an SMA connector in just the right place for it to stick out the end of the case as seen in the picture above. It gives him better range, but since speed depends on how much traffic the wireless node is under, it’s not a guarantee that you’ll get a snappier connection after this hack.
a.ntivir.us wanted to use a different antenna for their Netgear mbr624gu WiFi router. Unfortunately, this model comes with an antenna that is not removable. As with other antenna retrofits, this involves no soldering. But because there is already a mounting area for an antenna, no case altering is needed either. After opening the router with a Torx driver it was discovered that the non-removable antenna was connected to the board with a mini rf connector (U.FL). The antenna and its mounting bracket were removed and a U.FL to RP-SMA adapter was put in its place using a washer to secure it to the rear plate of the router. Now any external antenna can be used and the router still looks brand new.
When you need something quietly bending or moving, don’t underestimate SMA’s (or Shape Memory Alloys). The Living Glass project by architects [David Benjamin] and [Soo-in Yang] catalogs an experiment in building interactive, flexible, “breathing”, walls out of SMA wire and microcontrollers. Although they use Basic Stamps, the project could easily be extended to more cost-effective microcontrollers for large surfaces. The project is well documented with videos (AVI) of each prototyping step and even includes the ideas that were ultimately scrapped. Even if you don’t build a wall of interactive gills, this project should give you plenty of ideas for uses of SMA wire embedded in semi-flexible materials.