Eindhoven (NL), November 2022
Prize for better measurement of gravitational waves
During the 21st edition of the Precision Fair, held this year in Den Bosch for the second time, the Wim van der Hoek Award was presented under the auspices of DSPE (Dutch Society for Precision Engineering). The prize went to Dennis Struver, who designed an active vibration isolation system for cryogenic application at JPE in Maastricht-Airport (NL) and subsequently graduated on this design from Eindhoven University of Technology (TU/e). This system works at extremely low temperatures to make a better, more sensitive gravitational wave detector. According to the jury, his design is a “best practice” of the design principles for precise movement and positioning in the spirit of Wim van der Hoek. “Especially the clever folding of the construction, because of the limited space, and the use of a one-piece straight guide are fine examples of innovativity.”
The second day of the Precision Fair 2022, Thursday 17th November in Den Bosch (NL), featured the presentation of the Wim van der Hoek Award. This award (also known as the Constructors Award) was introduced in 2006 to mark the 80th birthday of the Dutch doyen of design engineering principles, Wim van der Hoek (1924-2019). The Constructors Award is presented every year to the person with the best graduation project in the field of design in mechanical engineering at a Dutch or Belgian university of technology or university of applied sciences. This award includes a certificate, a trophy made by the Leidse instrumentmakers School and a sum of money, sponsored by TU/e institute EIASI.
Criteria for the assessment of the graduation theses include the quality of the design, substantiation and innovativeness, as well as suitability for use as teaching materials. The jury, under the presidency of DSPE board member Jos Gunsing (MaromeTech), received a total of five nominations, coming from Avans University of Applied Sciences in Breda (NL), Fontys Engineering University of Applied Sciences in Eindhoven (NL), KU Leuven University (Belgium), TU/e and the University of Twente in Enschede (NL).
Measuring gravitational waves even more sensitively
The Wim van der Hoek Award 2022 eventually went to Dennis Struver, who studied Mechanical Engineering at TU/e. He graduated this spring on the design of a vibration isolation system for application under cryogenic conditions. This system can make a gravitational wave detector even better and more sensitive. Gravitational waves were predicted by Albert Einstein’s general theory of relativity, and astronomers study these very weak signals that arise in the deep universe, for example when two black holes collide. Only since 2015 have direct measurements been possible, with kilometers-long detectors built in the US and Italy. Work is currently underway in Europe on a successor that – thanks partly to Struver’s design – should be able to measure even more sensitively and thus detect even more gravitational waves. This is the Einstein Telescope, the location for which has not yet been determined. One of the candidates is the Maastricht-Aachen-Liège triangle, where the detector could be installed deep underground in the marl, protected from all above-ground disturbances.
The Einstein Telescope should get its improved sensitivity, among other things, from working at ultra-low temperatures. This requires cooling, but commercially available cryocoolers produce noise that interferes with the measurement. Struver designed a cryogenic active vibration isolator to counteract the effect of the noise. “A very elegant design,” the jury judged. “Dennis has shown that he is perfectly capable of coming up with an innovative mechanical and mechatronic design, including control, and analysing it for critical aspects. For a well-thought-out design, he looked at various design principles and combined the final application with thermal decoupling of the system, to prevent heating by the environment. He has great inventiveness and analytical skills and works very independently, although he also knows how to approach people for relevant input.”
According to the jury, Struver’s design is a “best practice” of the design principles for precise movement and positioning in the spirit of Wim van der Hoek. “Especially the clever folding of the construction, because of limited space, and the use of a one-piece straight guide are fine examples of innovativity.” Unfortunately, due to the late delivery of components, he was unable to build the complete system in time for testing. After completing his graduation work, he took tests later on his own initiative. The jury appreciates this effort.
Completing the circle
Struver carried out his assignment at JPE in Maastricht-Airport. This precision technology company specializes in, among other things, the development of scientific instruments that work at cryogenic temperatures, for example in a satellite in space, in a telescope on top of a high mountain, or in a gravity detector underground. In the early 1980s, JPE founder Huub Janssen was one of the last graduates of Wim van der Hoek, who in addition to his work at Philips also had an appointment as a part-time professor at the TU/e. With the prize named after Van der Hoek being awarded to Dennis Struver, the circle is now complete.