Smoothie: Bell-Everman's new Z-axis
Bearing limits tilt to 1 arc-sec and handles travel of 25 mm or
Like a window shade, this Z-axis bearing unwinds thin, 0.003-inch strips, or
flexures, as it moves, achieving high parallelism without backlash, friction, or
rolling contact. Designer Michael Everman Inc. claims that the bearing's top and
bottom surfaces can be held parallel within 1 micron through a stroke. The
bearing can move nearly half the height it stands, making for a compact setup.
Laser welding attaches the flexures to the rollers. Three flexures per roller
are sized and oriented to equalize their spring constants.
Bell-Everman aims the bearings at semiconductor metrology, where optical focusing requires silicon wafers to move vertically in small nanometer increments. Low angles of tip and tilt are necessary to maintaining focus. Today, such optical focusing typically relies on two stages. A wedge screw makes any coarse moves. Then, a piezoelectric stage handles fine moves of up to 0.5 mm. Tilt during translation usually falls between 10 and 15 arc-secs in these stages. The new bearing limits tilt to 1 arc-sec and handles travel of 25 mm or more.
The company plans to offer the bearing with voice coil, piezo, or ball screw drivers. Any driver could be used, but the company recommends one that complements the bearing's knack for working clean and being maintenance-free.
Are they robots or androids? We're not exactly sure. Each talking, gesturing Geminoid looks exactly like a real individual, starting with their creator, professor Hiroshi Ishiguro of Osaka University in Japan.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.