Originally Published MPMN March 2003

SPECIAL

Piezoelectric motor has four legs up on competition

A piezoelectric micromotor that combines power, nanoscale resolution, and speed in a compact package also boasts a simple, robust design. It is a cost-effective alternative to conventional electromagnetic linear motion systems, according to Peo Sollerud, marketing manager at PiezoMotor Uppsala AB (Uppsala, Sweden; www.piezomotor.com). Pump systems used in insulin delivery and anaesthetic devices would also benefit.

Constructed in a single piece with four movable appendages, the Piezo Legs motor operates without gears or a mechanical transmission. Applying voltage to the motor sets in motion a synchronized forward or backward movement of each pair of legs, allowing the motor to "walk up to several centimeters per second, with a resolution down to 10 nanometers," says Sollerud. "It can lift up to 1000 times its weight and attains 8 N of pulling force without the use of drive screws, gears, or other mechanical subassemblies," he adds.

The motor's motion mechanism is composed of thin piezoceramic layers sandwiched between conductive materials. More than 100 layers can be stacked on top of one another, allowing the motor to run exclusively on battery power. Movement is fine tuned, and each leg is fitted with a wear-resistant sole.

Because of the motor's small size and backlash-free operation, "we see micromanipulation in surgical and laboratory instruments as a field of application," says company CEO Per Oskar Lithell. The firm has a number of medical-related projects in the works, adds Lithell, but nondisclosure agreements prevent him from providing any details.

Company engineers focused on keeping the design simple when developing the motor to enable its production in large quantities without sacrificing precision. The motor's properties and performance specifications can be easily adapted to suit an array of applications. The firm has the expertise to manage the complete development process of a motor or motion control system, or customers can simply purchase motors built to their specifications.

Norbert Sparrow, Susan Wallace, and Zachary Turke

Copyright ©2003 Medical Product Manufacturing News