Low-cost quest

Researchers at a UK university plan to develop a piezoelectric motor suitable for low-cost mass production by the end of the year.

Cranfield University hopes to commercialise the motor as a smaller, cheaper alternative to conventional electromagnetic motors used in a many everyday devices such as camera zoom lenses and toys.

Piezoelectric motors are based on the deformation that occurs when piezoelectric materials are subjected to an electric field, producing high-speed ultrasonic vibrations. Controlling this effect allows motors to be created with fewer parts than are needed for electromagnetic systems. Piezoelectric devices could offer a host of benefits over existing electromagnetic and electrostatic technologies, according to Cranfield.

The motors need no gears, have low power consumption and hold their position by friction locking when power is off. Rotation can be reversed simply by reversing the electric field, while they also offer good stop/start response and a greater torque-to-weight ratio. While Japan has forged ahead with the development of the technology, Cranfield claimed the UK, and Europe in general, have lagged behind.

The university has been working on new designs for piezoelectric motors for several years, and now plans to develop a working prototype capable of commercial production by the end of the year based on work patented during earlier research.

Professor Roger Whatmore of Cranfield’s School of Industrial & Manufacturing Science, said that the motor had been tested for use in mechanical devices in a range of sizes down to nanoscale.

‘We’ve now got to engineer it into a demonstrator and see if we can lay the foundations for building a business.’

Whatmore said the motor could be used in many mass-market consumer electronics applications, ranging from toys and cameras to the vibrating mechanism in mobile phones. ‘There are many devices in which you need small, low-cost motors,’ he said.

Whatmore said he hoped the motor could be manufactured at a cost ‘in the tens of pence’.

The prototype project is backed by a six-month grant from the EPSRC. Cranfield is also engaged in other research relating to piezoelectric technology, including the development of lightweight motors for micro-aircraft.