Very cool widget from British firm RTL Materials, who’ve figured out a trick for making composite tubes that are pre-stressed, like a tape measure, such that they want to roll up into a rigid round tube structure when unfurled from a flat, coiled state. Unlike a tape measure, however, these “bistable reeled composites” are also […]
Shape-memory metals get a fair amount of attention, but shape memory polymers exist, too. In fact, heat-shrink tubing is a familiar example of a simple shape-memory effect in a polymer. This video uploaded by MIT researcher Vikas Srivastava back in 2009 is a more impressive demonstration of heat-induced shape recovery. The plastic material is tBA […]
Those of you, um, enthusiastic enough to remember Star Trek IV may recall the scene embedded here. If not, let me set up the clip: The crew of the Enterprise has gone into the past to retrieve some whales, OK? And take them “back to the future,” to coin a phrase. But Scotty has a […]
On Friday, I wrote about the development of amorphous or “glassy” metal alloys, in which the atoms are packed together with no regular crystal structure. At the microscopic level, almost all metals are made of crystal grains, which can be bigger or smaller depending on how the metal has been heat treated. Amorphous alloys, recall, […]
Use the camera in your Android smartphone to detect radiation with the Radioactivity Counter app from Rolf-Dieter Klein. Just place a small piece of black tape over the camera lens, calibrate for ambient noise, and you’ll be ready to take readings in no time. The app uses the device’s built-in CMOS sensor to detect primary […]
At the atomic scale, generally speaking, solids are either crystalline or amorphous. In crystals, the atoms or molecules fill space in a repeating, orderly arrangement, like stacked cannonballs or cells in a honeycomb. Table salt is a handy example. In amorphous materials, however, the atoms or molecules are packed together randomly, without repeating arrangements. Glass […]
This article from seasoned acoustical engineer Eric Wolfram of AcousticsFREQ.com may be short on flashy pictures, but it is long on technical info and great practical advice from someone who obviously knows his business.
