When it comes to motion systems, small is bigger than ever. “Many things that were once fixed are becoming mobile,” says David Henderson, chief executive and technology officer for New Scale Technologies, a maker of tiny linear motors. “And mobility and miniaturization go hand in hand.” Mobile phones are one obvious example of this trend because their increasingly sophisticated camera optics require miniscule, yet capable, actuators to enable features like optical zoom and autofocus. But all sorts of military, medical, optical, industrial and laboratory automation devices are also under pressure to miniaturize. Here's a look a three recent developments with the smallest motion systems.
High-Force Stacked Actuators
Physik Instrumente (PI) has introduced a new series of piezoelectric stacked actuators and a related line of linear amplifiers for use in high-force, high-dynamics applications requiring micro- or nano-scale motion. Consisting of four models (P-212, P-216, P-225 and P-235), the new actuator series is built around PI's PIC 255 PICA Power piezoceramic stacks. They come with load capacities from 2,000 to 30,000 N and travel ranges from 15 to 180 µm. According to PI Marketing Director Stefan Vorndran, all of the actuators provide sub-nanometer resolution and are available with position feedback. All also feature an integrated preload capability — useful in push-pull applications, as well as dynamic applications such as precision machining, active vibration damping and adaptronic systems. Five RoHS-compliant high-voltage amplifiers ranging from 1 to 2,000W of power are available to drive the new pre-loaded piezo actuators. All are delivered preset to provide 0 to 1,000V output voltage and most can also be run in bipolar mode.
Development Aid For The Tiniest Motors
Thanks to its SQUIGGLE line of miniature linear motors, New Scale Technologies already puts together some of the world's smallest motion systems. Now a technology development partnership with austriamicrosystems, a supplier of analog ICs, promises to make New Scale's micro motion systems even smaller while improving their resolution and efficiency. The two companies plan to integrate New Scale's ultrasonic motors with custom control and position-sensing ICs from austriamicrosystems. According to David Henderson, New Scale's chief executive and technology officer, austriamicrosystems has the expertise needed to shrink the electronics that complement the motor in a complete closed-loop motion control system. “This partnership will allow us to produce a new line of disruptively small motion systems,” he says. How small? Well, the complete closed-loop systems won't likely be much bigger than the SQUIGGLE motors themselves. The latest of these motors, for example, measures just 1.8 x 1.8 x 6 mm. Yet it still packs a punch. It can push axial loads as high as 30 gm — or nearly 200 times its own 0.16-gm weight. And it travels at speeds up to 7 mm/sec. austriamicrosystems, which invested $6 million in New Scale as part of this technology development pact, could help enhance the performance of micro motion systems in other ways, too. “Their linear position sensing technology is really quite unique and will help us target resolutions close to one micrometer,” Henderson says. He adds, austriamicrosystems' also offers power management technology that could result in more efficient systems, though he says it's too early in the development process to quantify any efficiency gains. Applications for jointly developed micro motion systems include the increasingly sophisticated cameras on mobile phones, electronic locks and fasteners, medical devices and a variety of other applications needing truly tiny, low-power actuators.
Single Axis in a Box
Maxon Motor, a leader in high-precision microdrive systems, has come out with a new motion control development package that allows users to configure a single-axis of motion easily. “Our idea was to put together a kit that contains everything you need for a single-axis of position, speed or torque control,” says Maxon Applications Engineer Joe Martino. Called the Freedom Series, this all-inclusive package is configured around any of four different brushless motor options ranging in size from 16 to 40 mm in diameter and up to 1/6 hp. The package also includes Maxon's GUI configuration software and easy-to-follow instructional wizards. Cables and connectors are also part of this plug-and-play package. Finally, Maxon has also included its newly released book, “The Selection of High-Precision Microdrives.” The complete package is available for $600 to $700, hundreds less than configuring a similar package from individual components.