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.
Advertised as the "Most Powerful Tablet Under $100," the Kindle Fire HD 6 was too tempting for the team at iFixit to pass up. Join us to find out if inexpensive means cheap, irreparable, or just down right economical. It's teardown time!
The increased adoption of wireless technology for mission-critical applications has revved up the global market for dynamic electronic general purpose (GP) test equipment. As the link between cloud networks and devices -- smartphones, tablets, and notebooks -- results in more complex devices under test, the demand for radio frequency test equipment is starting to intensify.
Much of the research on lithium-ion batteries is focused on how to make the batteries charge more quickly and last longer than they currently do, work that would significantly improve the experience of mobile device users, as well EV and hybrid car drivers. Researchers in Singapore have come up with what seems like the best solution so far -- a battery that can recharge itself in mere minutes and has a potential lifespan of 20 years.
Some humanoid walking robots are also good at running, balancing, and coordinated movements in group settings. Several of our sports robots have won regional or worldwide acclaim in the RoboCup soccer World Cup, or FIRST Robotics competitions. Others include the world's first hockey-playing robot and a trash-talking Scrabble player.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.