3D-printed surfaces steer gas particles and stabilize quantum sensors

Researchers at the University of Nottingham have used additive manufacturing to develop surface structures that deliberately deflect gas particles, thereby improving the operation of quantum sensors. The work was carried out at the School of Physics and Astronomy and addresses a central challenge of portable quantum technologies: controlling residual gases in high-vacuum environments. The results were published in the scientific journal Physical Review Applied.

Quantum sensors use individual atoms or other quantum systems to measure quantities such as magnetic fields or gravity with extremely high precision. However, their sensitivity also makes them susceptible to disturbances caused by gas molecules, which is why they must be operated under vacuum. Even in technically sophisticated vacuum systems, unwanted particles occasionally enter the measurement region and generate noise. The Nottingham group led by L. Hackermueller addresses this issue with a passive approach based on 3D-printed surfaces.

Specifically, titanium alloys were additively manufactured and equipped with finely structured patterns, including hexagonal recesses and conical protrusions. These textures increase the likelihood that an incident gas atom will interact multiple times with the surface and be preferentially reflected in specific directions. In a disk-shaped demonstrator that can be integrated into standard vacuum chambers, this approach significantly increased the efficiency of a surface-based vacuum pump. Measurements showed up to a 3.8-fold higher pumping rate per area compared to smooth reference surfaces.

“We are still discovering the most effective surface textures; promising candidates include a hexagonal pattern similar to a honeycomb and an intricate three-dimensional pattern derived from geometry-inspired artwork. This relatively low-tech innovation can substantially improve advanced quantum technologies”, said Nathan Cooper, Research Fellow in the School of Physics and Astronomy and lead author on the pape.

PhD student, Ben Hopton, co-author on the paper said: “What’s exciting about this work is that relatively simple surface engineering can have a surprisingly large effect. By shifting some of the burden from active pumping to passive surface-based pumping, this approach has the potential to significantly reduce, or even remove, the need for bulky pumps in some vacuum systems, allowing quantum technologies to be far more portable.”

In the long term, the researchers see potential to replace part of the currently active vacuum generation with such passive, 3D-printed components. This could make vacuum systems more compact and facilitate the use of quantum sensors outside specialized laboratories without compromising measurement accuracy.