Italian precision manufacturing company Weerg was tapped to additively manufacture essential elements of the undersea Cubic Kilometer Neutrino Telescope (KM3NeT). The telescope, which is run by Nikhef, the Dutch National Institute of Subatomic Physics, is located in the depths of the Mediterranean Sea and takes up more than a cubic kilometer of the seafloor. KM3NeT helps scientists research the building blocks of our universe, their mutual forces and the structure of space and time: black holes are one subject of this research.
KM3NeT contributes to the search for the properties of elusive neutrino particles. Through the study of neutrinos, researchers hope to discover the origins of cosmic rays and the cause for natural particle acceleration in the universe. Scientists in the international network will use the telescope to search for neutrinos from distant astrophysical sources, such as supernovae, gamma rays or colliding stars. KM3NeT’s thousands of optical sensors are able to detect the faintest lights in the deep sea from charged particles originating from neutrino-and-Earth collisions.
KM3NeT consists of digital optical modules (DOMs): football-sized glass spheres filled with 31 phototubes and anchored to the sea floor. DOMs are arranged in hundreds of lines about a kilometer long .
Nikhef turned to Weerg to create semi-spheres measuring 380 mm, which are brought together to hour the telescope’s optical sensors. These finished spheres are precision-engineered to ensure correct specifications for each sensor cluster. Weerg printed the semi-spheres with its new installation of HP Multi Jet Fusion 5210 3D printing technology.
“The first order arrived about two years ago and since then the collaboration has continued with regularity, even for higher and higher runs,” said Francesco Zanardo, general manager of Weerg. “So far, we have produced about 300 of these spheres, which have the particularity of having the maximum size that can be printed with HP systems.” Orders are coming in regularly from Nikhef and its European partners. In addition to the spheres, numerous smaller components have been printed in 3D, again for the KM3NeT project.
The material chosen to manufacture the Cubic Kilometer Neutrino Telescope’s sensor housings is Nylon PA12, which Weerg offers alongside PA11 and polypropylene. PA12 is rigid and resistant, which makes it ideal for functional prototypes and final parts that need to have high chemical resistance to oils, greases, hydrocarbons. Nylon PA12, moreover, absorbs very little humidity, thus guaranteeing excellent performance in any environment and condition.
Edward Berbee of Nikhef says: “We have been working on this project since 2013 and over the years we have contacted about 50 different suppliers. Initially, the prices of 3D printing were unfeasible, then we found a supplier with reasonable prices, but he was only able to make the component in 2 divided parts that we had to glue afterwards. This solution was certainly not optimal, so we continued to analyze new technologies, until we discovered the interesting performance of HP’s Multi Jet Fusion systems. While we were considering whether or not a research institution like ours should purchase the system, we read an article announcing Weerg’s record-breaking installation of HP 3D printers”. Berbee and his team immediately placed an initial test order, which proved to be excellent in terms of service and quality. Another extremely attractive benefit for Nikhef was the option of painting the parts offered by Weerg, which the Institute previously did manually: “The parts we order from Weerg are painted black at a cost that is absolutely competitive with the resources we had to deploy.”