Les Hunt visited one of the country's foremost suppliers of
piezoelectric ceramics to discover the wide applications of these
versatile materials, and their use in the customisation of all manner of
devices, from automotive parking sensors to blood flow monitors
If you drive a car that has a rear distance warning system to help you
park in a tight space, then likely as not, the row of sensors along the
rear bumper have at their heart, ceramic sensor elements supplied by one
of the world's foremost suppliers of piezoelectric ceramics, Southampton
based Morgan Electro Ceramics (MEC). Indeed, the company currently
produces around 20 million of these devices for the automotive market,
along with more specialised piezo-ceramic devices, including pre-ignition
detectors, fuel level detectors, fuel injection actuators and crash
sensors that take advantage of the piezoelectric effect. But the
automotive market is not the only sector served by this company.
Morgan Electro Ceramics is a subsidiary of Morgan Crucible, which has a
worldwide reputation for innovation in the use of carbon, ceramic and
magnetic materials, and is a member of the Morgan Technical Ceramics
group. At the Southampton site lead zirconate titanate (PZT) compositions
of ceramic are processed from the raw powder material stage through
firing, to the finished blanks and custom shapes that are ready for
machining and further downstream assembly operations. These components
are used extensively in the manufacture of ultrasonic transducers and
sensor assemblies, actuators, accelerometers and hydrophones, to mention
just a few applications examples.
Quite apart from its high volume parking sensor business, the company's
main activities lie in the design and manufacture of customised sensors,
where the piezoelectric ceramic element forms just part of a complex,
precision built sensor assembly. The company is well equipped for this
type of work, which often involves consultations with clients at the very
earliest stages of a project to gauge performance expectations,
environmental exposure and the like. Making use of its advanced in-house
computer modelling resources (finite element analysis), the company is
able to study the dynamic stresses within component parts of a proposed
assembly prior to prototyping and testing.
Morgan Electro Ceramics produces a broad range of PZT compositions to
meet different mechanical, environmental (particularly temperature) and
electrical performance criteria. A good example of this is the recent
introduction of PZT-5K1-HD, a piezoelectric ceramic that is tailored for
medical device applications. This material provides increased coupling
values and superior dielectric constant - useful properties for low-power
sensors used in blood pressure gauges, vascular flow monitors and medical
imaging equipment. The company also takes pains to understand the
acoustical properties of materials used in the construction of the sensor
assembly, including the adhesives used to bond the ceramic, and the
damping materials that determine the directional properties of the
sensor, all of which can have a profound effect on its performance and
life expectancy.
Morgan Advanced Ceramics is active in a number of sectors. In addition to
those already mentioned, the company produces custom components for
industry (power ultrasonics for cleaning applications, gas laser
discharge capacitors, level and flow sensing, accelerometers); defence
and aerospace (active and passive sonar devices, gyros, fuel level
sensing); IT (anti-vibration devices, actuators for read/write heads) and
telecommunications (base station cavity filters).
To gain a better understanding of piezoelectric ceramic devices and their
applications, visit the company's web site, which maintains a library of
technical papers. Locate this story on the DPA site for a direct lin