IEEE MEMS 2004
Maastricht, The Netherlands, January 25-29^th. www.mems2004.org

Polecer 2004
Materials, Technology and Design of Integrated Piezoelectric Devices 2nd - 4th February 2004, Courmayer, Italy http://www.ata.it/italiano/manifest/2004/02-04Febbraio/conference.htm

Smart Structures/NDE 2004
March 14-18^th 2004, San Diego, California, USA. www.spie.org/Conferences/Calls/04/ss

ISIF 2004
The 16th International Symposium on Integrated Ferroelectrics. April 5-8^th, Gyeongju, Korea. www.isif.net

Electroceramics IX
31^st May - 3^rd June 2004, Cherbourg, France. www.chbg.unicaen.fr/lusac/ELECTROCERAMICS/accueil.html

Mark Stewart from NPL will be attending and presenting a paper on some recent measurements made with our Berlincourt system.

Measurement Issues associated with the Berlincourt technique

Markys Cain and Mark Stewart

The use of the Berlincourt technique to measure the piezoelectric coefficients of bulk piezoelectric ceramics is a very popular method because of its simplicity and speed of operation and moderate price. However, an experimental programme at NPL has identified many measurement issues associated with the technique that incur error and variability in measured data. This presentation will describe the main sources of error, most notably the level of static pre-load on the sample, and will explore ways in which to minimise the variability that this leads to.

Actuator 2004
9th International Conference on New Actuators. 14-16^th June 2004, Bremen, Germany. www.actuator.de

From the UK Paul Weaver will be presenting two papers on work carried out at Servocell.

THERMAL RESPONSE OF LARGE MOVEMENT LOW POWER DC ACTUATORS FOR USE IN LOCK AND VALVE MECHANISMS

P.M Weaver, Y. Zheng

The effective use of piezo ceramic actuators in applications such as lock and valve mechanisms requires a large movement that is stable over a wide operating temperature range. It is well known that piezo-ceramic properties vary with temperature, but much of the existing research relates to cyclical operation for applications such as ultrasound and sonar. The effects of the thermal variations on the static and low frequency performance of an actuator are much less well understood. This paper presents a study of the thermal behaviour of the actuators used in Servocell lock and valve mechanisms and relates these to the properties of the piezo ceramic and the parameters of the device construction. The application of the actuator is demonstrated by the performance of the Servocell Active Latch lock mechanism which deploys very compact low power piezo actuation in electronic access controls.

ELECTRONIC DOMESTIC GAS VALVE PROPORTIONALLY CONTROLLED USING PIEZO ACTUATORS

P. Mandurino, P.M. Weaver

Piezo actuation offers significant benefits for gas flow control compared to conventional technology. These include the capability to deliver robust proportional control with silent operation and low power consumption. A completely innovative proportionally controlled piezo actuated electronic gas valve for domestic appliances has been developed by in collaboration between Servocell and Diamond-H controls. The valve is driven by a very compact, low profile actuator delivering a high force with a large movement. This paper describes the optimisation of the actuator design for effective operation of the valve. The very small amount of material and the very limited number of parts makes it a very simple, low cost device whilst also providing outstandingly low power consumption.

UK Ferroelectrics 2004
UK Ferroelectrics, 14-15^th June 2004, Cranfield University, UK http://www.materials.leeds.ac.uk/ferroelectrics/default.htm

Markys Cain and Mark Stewart from NPL will be attending and presenting a poster on the new AIMS interferometer system.

Characterisation of thin film piezoelectric materials by differential interferometric techniques

Markys G Cain

Piezoelectric thin films are considered emergent materials for integration within Micro Systems Technology (MST) or MEMS devices. The development of suitable measurement facilities to characterise the materials functional properties is complicated by the fact that the film is often attached to a substrate which acts to clamp the film thus affecting the system performance. This talk will describe a new differential interferometer system based on common path Jamin optics and measurement lock-in techniques that is able to analyse the displacements of the thin film to 10's of pm resolution. The film/substrate acts as a natural bending element and this effect means that the displacement measurements must be carefully controlled to minimise any substrate bending. The system designed at NPL is able to measure the degree of substrate bend so that an 'effective' piezoelectric coefficient may be calculated. Results will be shown for ceramic monolithic materials, quartz single crystal material and sol-gel derived thin and thick films of PZT on Si substrates. Further metrological issues will be addressed and future plans described.

European Workshop on Piezoelectric Materials
4th European Workshop on Piezoelectric Materials, 21-23 july 2004, Montpellier, France.http://www.lpmc.univ-montp2.fr/~4ewpm/index.html

IEEE UFFC 2004
IEEE International Ultrasonics, Ferroelectrics, and Frequency Control 50th Anniversary Joint Conference , 24-27 August, 2004, Montréal, Canada. http://ewh.ieee.org/soc/uffc/

ECAPD-7 2004
European Conference on Applications of Polar Dielectrics (ECAPD-7), 6th - 9th September 2004, Liberec, Czech Republic.http://www.mechatronika.cz/ECAPD7/