Micro-motors take over when conventional designs reach their limits

Paul Boughton

The increasing trend towards greater product miniaturisation poses a real challenge for today’s design engineers. When confronted with ever-smaller spaces in which to locate an electromagnetic motor, they are finding that conventional technology has all too often reached its performance limits as the work possible to do is reduced dramatically.

Now that situation is changing, says PiezoMotor AB.

Confined spaces no longer mean unwanted motor compromises. Piezoelectric motor technology now offers manufacturers a way to keep on miniaturizing their designs and improving performance without having to change their motion solution. Very often, piezo motors fit where nothing else will.

This means that micro-motor manufacturers are becoming more and more involved with product design engineers. As well as offering extreme miniaturization, piezoelectric motors are more accurate than traditional direct current and stepper motors. Movement accuracy that is thousands of times smaller than a millimetre is achievable, for example.

Small piezoelectric motors with micron and sub-micron positioning are much sought-after in many industrial sectors today. Typical applications are found in semiconductor manufacturing, optics, telecoms, medical technologies and the defence industry.

By taking thousands of steps per second, even in the sub-micrometre range, a linear stage can move several centimetres during this time. Pulling forces can extend up to several hundred Newton. The need for gears, mechanical transmissions, rotors, stators or ball-bearings is also eliminated.

As well as being very compact and simple, a Piezo LEGS motor is highly energy efficient. It consumes no energy at rest, which is invaluable for ‘move-and-hold’ applications such as linear motorized guides or turning and holding an optical object, as well as for low power consumption products. As noted above, sub-micron resolution extending to single nanometre level and below is available when required. Moreover, Piezo LEGS technology works just as well for both linear and rotary motors, and new models in both categories have recently been launched on the world market.

Despite their size and simplicity, Piezo LEGS motors fulfil many key manufacturing needs. Their outstanding linear positioning resolution and back-lash free motion make them popular for high-precision systems as well as high-volume uses such as fixturing and alignment in factory automation.”

In a broader perspective, manufacturers also appreciate the fact that Piezo LEGS motors are generally delivered ready-to-use and can be installed with just a few screws. This helps them simplify product design and cut overall production costs. Furthermore, since the required piezo ceramic blocks are produced in-house at PiezoMotor’s facilities in Sweden, motor elements can be easily made longer or shorter, thicker or thinner. Simple and economical OEM customisation is thus within easy reach.