Photo copyright MESSE BREMEN/Jan Rathke
Photo rights MESSE BREMEN/Jan Rathke
New actuators can position with the highest accuracy, drive micro-pumps, reduce rotor blade vibrations, enable teleoperations via data gloves and much more. Current developments are the theme of the 16th ACTUATOR convention at Messe Bremen. From Monday 25 to Wednesday 27 June 2018, international experts from science and industry will present their latest findings at the event's 30th anniversary. The agenda includes 13 sessions with 84 lectures, and a session with 60 poster contributions. An accompanying exhibition will be held in parallel to the conference.
Some topics are always well-represented. "In particular this applies to piezo actuators, which have emerged very strongly in all industries. Nevertheless, there are always new trends", says Dr. Hubert Borgmann. He has been organising ACTUATOR in close cooperation with the 25 members of the programme committee for many years.
For example, Prof. Dr Kenji Uchino from Pennsylvania State University, a member of this committee, will be presenting technologies that may help to prevent disasters or at least to reduce their consequences. This makes it possible to construct earthquake-proof buildings, improve earthquake and tsunami predictions and increase reactor safety. Uchino's colleagues are now developing a high-temperature technology that will make it possible to study the condition of uranium fuel rods in reactors. Uchino considers this problematic, as our understanding of the effects of radioactivity on piezoelectric materials is still limited.
High temperatures and radioactive materials – Ionix Advanced Technologies in the UK is also working on this problem. Background: applications such as valve controls for chemical or oil/gas facilities, for example, have to withstand extreme heat. Many materials can actually do that, according to Dr. Tim Comyn, the Technical Director at Ionix. However, as a result their piezoelectric effect – such as linear expansion d33 – is low.
Comyn and his colleagues have developed a bismuth-based perovskite family of materials that is pushing these boundaries. Their linear expansion reaches more than 90 picometres per volt (pm/V) and they can be used from minus 197 to over 400 degrees Celsius. "This means the actuators are as versatile as lead zirconate titanate (PZT) drives, but tolerate much higher temperatures", says Comyn.
Some practical applications of new actuators being presented at ACTUATOR focus on aerospace and medical solutions. Scientists at the Scuola Superiore Sant'Anna, Pisa, and the École Polytechnique Fédérale de Lausanne are working on soft actuator systems for surgery. Actuators like these are versatile, but their lack of rigidity means power transmission is poor and they have difficulty in picking up loads, such as a functional unit on the tip of the device. This is why concessions have often been necessary in terms of softness until now, especially in medical endoscopes.
The researchers are working out a solution operating similarly to an elephant's trunk, says PhD student Haider Abidi. "Elephants can bend the tips of their trunks and at the same time stiffen another section, so that they can pull up plants, for example". To achieve the same effect, the group is affixing fibres with a core made of a low-melting alloy (variable stiffness fibres, or VSF) to the actuator, which consists of an elastomer with pressure chambers inside it. The heat causes the fibre core to melt in specified areas allowing the actuator to be warped. When the VSFs cool down again, they retain their current shape, making them easy to work with.
ACTUATOR has been hosted by Messe Bremen since 1988. It is the world's largest convention in its field and is held every two years. The organisers expect around 300 specialists from all over the world to attend this year.
For more information please visit www.actuator.de