Robo-Builder advances to market

When Bill Gates says the next great marketplace will be personal robotics, it's hard to see how this will be true. But here's a clue that reveals another advance in this new generation of machines.

Honda is showing this 'walking device' which uses flat brushless motors with a built-in control system.

An earlier post, Here Comes the Robo-Builder, shows how robots fitted to construction workers can help lift heavy panels, hold materials for fastening, or prevent strain and injury.

The "tool-belt" icon of today's builder might be in for a surprising shift soon.

Rip to a point

Trying to peel wallpaper? Why doesn't it roll off in a straight line instead of tearing off in pointed shards?

Lifting tape from a stubborn roll? It will likely rip to a point, a frustrating triangle that leaves a sticky and unusable remnant. Removing a label? Once again, the label will verge into triangles.

Pedro Reis, an applied mathematics instructor at MIT, says, "This pattern, where two cracks propagate toward each other and meet at a point, is extremely robust. It applies not only to wallpaper but other adhesives such as tape, as well as nonadhesive plastic sheets such as the shrink-wrap that envelops compact discs. It even extends to fruit: The skin on a tomato or a grape typically forms a triangle when peeled off. This has happened to everyone. it's frustrating.”

The team found that those ubiquitous triangular tears arise from interactions between three inherent properties of adhesive materials: elasticity (stiffness), adhesive energy (how strongly the adhesive sticks to a surface) and fracture energy (how tough it is to rip).

[more at Science blog]

New gutter design

Busted gutters in snow country are the norm. Over the years the costs climb, foundations fail, leaks wreck soffits and our roofs rot.

An Australian inventor turned the gutter upside down so that snow and ice slip over a smooth surface while water wicks underneath into the gutter channel.

See for yourself at SnowGutters.com.