Medical Device Link.

Originally Published EMDM September 2004

Technology News

Unaffected by magnetic fields and featuring noise-free operation, a piezoelectric motor developed by Elliptec has been designed into medical equipment.

Despite some desirable features, piezoelectric motors traditionally have been priced out of many applications. That may be about to change, if microtechnology firm Elliptec (Dortmund, Germany) has its way. The company has found some creative ways to rein in production costs without sacrificing performance. Its motor’s precise operation under harsh conditions and even strong magnetic fields has fueled interest among medical device OEMs, according to CEO Björn Magnussen.

Elliptec is a spin-off of Siemens AG, and it was that company’s use of piezo technology in the automotive field that led to the development of the Elliptecmotor. “Siemens used piezo technology to engineer fuel injectors at a reduced cost,” says Magnussen. “We decided to take that concept a step further.” By innovating on several fronts—processing the piezo material without grinding and scaling back the complexity and quantity of electronic parts—the company was able to dramatically cut costs.

The motor integrates a piezo element that oscillates when voltage is applied. A proprietary stator converts this oscillation into an elliptical movement at its tip. As the stator tip pushes against an object, microstep motion is produced. Changing the operating frequency from 85 to 95 kHz reverses the movement’s direction.

“The motor is very precise, accelerating and stopping almost instantly within about 10 µm without backlash,” says Magnussen. “Small and lightweight, it can be used in portable devices, and it withstands harsh environments. The motor can operate submerged in fluids or in a vacuum, and it is unaffected by strong magnetic fields. In addition, it is noise-free,” adds Magnussen.

Med-tech companies currently are using the product, and several more have shown an interest in it, says Magnussen, but confidentiality agreements prevent him from disclosing any details.

Copyright ©2004 European Medical Device Manufacturer