`World`s smallest` piezo actuator targets mass markets

A tiny new electrical actuator that could be mass-produced for applications in appliances, toys, pick-and-place systems and medical equipment, was unveiled at the recent SPS/IPC/Drives exhibition in Germany. The PiezoWave device (shown below) is the result of five years of development work by the Swedish firm, PiezoMotor, which describes it as "the world`s smallest linear piezo motor".

The company is hailing the development as "a true revolution in miniaturised motion" and predicts that it will open up applications that were previously impossible to motorise.

The robust miniature actuators provide a direct linear drive, without needing gears or leadscrews. They are 14mm long, 7.2mm wide and 4.4mm high. They can deliver a dynamic force of 0.1N and a holding force of 0.3-0.4N, over a stroke length of 8mm. They move in steps of 0.5-1 micron and are claimed to have cycle lives of more than 100,000 operations. In mass production, the PiezoWaves could cost less than €10.

The actuators work on a different principle to PiezoMotor`s earlier devices, which "walk" on dozens of piezoelectric "legs". The new actuators use an ultrasonic (80-100kHz) wave effect to propel central rods that are sandwiched between two piezoelectric layers.

The PiezoWave actuators use simple drive electronics and are said to be easy to integrate into applications. They operate from 3.3-5V supplies and draw 60-70mA (at 4V).

"We have been developing this groundbreaking micro motor technology since 2000," says Peo Solerud, PiezoMotor`s marketing director, "so you can imagine, it`s a great feeling finally being able to show it to the world, ready for OEM integration".

The PiezoWave devices are due to enter production soon, ramping up to volume production by the mid-2006.